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PL-3 or POS-PHY Level 3 is a network protocol . It is the name of the interface that the Optical Internetworking Forum 's SPI-3 Interoperability Agreement is based on. It was proposed by PMC-Sierra to the Optical Internetworking Forum and adopted in June 2000. The name means Packet Over SONET Physical layer level 3. PL-3 was developed by PMC-Sierra in conjunction with the SATURN Development Group .

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121-534: The name is an acronym of an acronym of an acronym as the P in PL stands for "POS-PHY" and the S in POS-PHY stands for "SONET" ( Synchronous Optical Network ). The L in PL stands for "Layer". There are two broad categories of chip-to-chip interfaces. The first, exemplified by PCI-Express and HyperTransport , supports reads and writes of memory addresses. The second broad category carries user packets over 1 or more channels and

242-588: A high-speed side (where the full line rate signal is supported), and a low-speed side , which can consist of electrical as well as optical interfaces. The low-speed side takes in low-speed signals, which are multiplexed by the network element and sent out from the high-speed side, or vice versa. Recent digital cross connect systems (DCSs or DXCs) support numerous high-speed signals, and allow for cross-connection of DS1s, DS3s and even STS-3s/12c and so on, from any input to any output. Advanced DCSs can support numerous subtending rings simultaneously. SONET and SDH have

363-403: A middle power , Canada's strong support for multilateralism and internationalism has been closely related to its foreign relations policies of peacekeeping and aid for developing countries . Canada is part of multiple international organizations and forums . While a variety of theories have been postulated for the etymological origins of Canada , the name is now accepted as coming from

484-467: A parliamentary system within the context of a constitutional monarchy —the monarchy of Canada being the foundation of the executive, legislative , and judicial branches. The reigning monarch is also monarch of 14 other sovereign Commonwealth countries and Canada's 10 provinces . The monarch appoints a representative, the governor general , on the advice of the prime minister , to carry out most of their ceremonial royal duties. The monarchy

605-478: A 'transport' in the OSI Model sense). Due to SONET/SDH's essential protocol neutrality and transport-oriented features, SONET/SDH was the choice for transporting the fixed length Asynchronous Transfer Mode (ATM) frames also known as cells. It quickly evolved mapping structures and concatenated payload containers to transport ATM connections. In other words, for ATM (and eventually other protocols such as Ethernet ),

726-500: A PDH DS1 signal. A VTG may instead be subdivided into three VT2 signals, each of which can carry a PDH E1 signal. The SDH equivalent of a VTG is a TUG-2; VT1.5 is equivalent to VC-11, and VT2 is equivalent to VC-12. Three STS-1 signals may be multiplexed by time-division multiplexing to form the next level of the SONET hierarchy, the OC-3 (STS-3), running at 155.52 Mbit/s. The signal

847-409: A SONET/SDH signal allows it to carry many different services in its virtual container (VC), because it is bandwidth-flexible. SONET and SDH often use different terms to describe identical features or functions. This can cause confusion and exaggerate their differences. With a few exceptions, SDH can be thought of as a superset of SONET. SONET is a set of transport containers that allow for delivery of

968-665: A consequence of European colonization, the Indigenous population declined by forty to eighty percent. The decline is attributed to several causes, including the transfer of European diseases , to which they had no natural immunity, conflicts over the fur trade, conflicts with the colonial authorities and settlers, and the loss of Indigenous lands to settlers and the subsequent collapse of several nations' self-sufficiency. Although not without conflict, European Canadians ' early interactions with First Nations and Inuit populations were relatively peaceful. First Nations and Métis peoples played

1089-554: A constitutional amending formula and the Canadian Charter of Rights and Freedoms . The Charter guarantees basic rights and freedoms that usually cannot be overridden by any government; a notwithstanding clause allows Parliament and the provincial legislatures to override certain sections of the Charter for a period of five years. Canada's judiciary interprets laws and has the power to strike down acts of Parliament that violate

1210-508: A critical part in the development of European colonies in Canada , particularly for their role in assisting European coureurs des bois and voyageurs in their explorations of the continent during the North American fur trade . These early European interactions with First Nations would change from friendship and peace treaties to the dispossession of Indigenous lands through treaties . From

1331-506: A distinguishing element of Canada's political culture. Peace, order, and good government , alongside an Implied Bill of Rights , are founding principles of Canadian federalism . At the federal level, Canada has been dominated by two relatively centrist parties practising "brokerage politics": the centre-left leaning Liberal Party of Canada and the centre-right leaning Conservative Party of Canada (or its predecessors ). The historically predominant Liberals position themselves at

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1452-585: A limited number of architectures defined. These architectures allow for efficient bandwidth usage as well as protection (i.e. the ability to transmit traffic even when part of the network has failed), and are fundamental to the worldwide deployment of SONET and SDH for moving digital traffic. Every SDH/SONET connection on the optical physical layer uses two optical fibers, regardless of the transmission speed. Linear Automatic Protection Switching (APS), also known as 1+1 , involves four fibers: two working fibers (one in each direction), and two protection fibers. Switching

1573-674: A process of increasing autonomy from the United Kingdom. This increased sovereignty was highlighted by the Statute of Westminster, 1931 , and culminating in the Canada Act 1982 , which severed the vestiges of legal dependence on the Parliament of the United Kingdom . Canada is a parliamentary democracy and a constitutional monarchy in the Westminster tradition . The country's head of government

1694-841: A separate colony in 1769. To avert conflict in Quebec , the British Parliament passed the Quebec Act 1774, expanding Quebec's territory to the Great Lakes and Ohio Valley . More importantly, the Quebec Act afforded Quebec special autonomy and rights of self-administration at a time when the Thirteen Colonies were increasingly agitating against British rule. It re-established the French language, Catholic faith, and French civil law there, staving off

1815-431: A temperate climate, with a mild and rainy winter. On the east and west coasts, average high temperatures are generally in the low 20s °C (70s °F), while between the coasts, the average summer high temperature ranges from 25 to 30 °C (77 to 86 °F), with temperatures in some interior locations occasionally exceeding 40 °C (104 °F). Much of Northern Canada is covered by ice and permafrost . The future of

1936-485: A variety of protocols, including traditional telephony, ATM, Ethernet, and TCP/IP traffic. SONET therefore is not in itself a native communications protocol and should not be confused as being necessarily connection-oriented in the way that term is usually used. The protocol is a heavily multiplexed structure, with the header interleaved between the data in a complex way. This permits the encapsulated data to have its own frame rate and be able to "float around" relative to

2057-466: Is 10 Gigabit Ethernet (10GbE). The Gigabit Ethernet Alliance created two 10 Gigabit Ethernet variants: a local area variant ( LAN PHY ) with a line rate of 10.3125 Gbit/s, and a wide area variant ( WAN PHY ) with the same line rate as OC-192/STM-64 (9,953,280 kbit/s). The WAN PHY variant encapsulates Ethernet data using a lightweight SDH/SONET frame, so as to be compatible at a low level with equipment designed to carry SDH/SONET signals, whereas

2178-491: Is added, and that SONET network element (NE) is said to be a path generator and terminator . The SONET NE is line terminating if it processes the line overhead. Note that wherever the line or path is terminated, the section is terminated also. SONET regenerators terminate the section, but not the paths or line. An STS-1 payload can also be subdivided into seven virtual tributary groups (VTGs). Each VTG can then be subdivided into four VT1.5 signals, each of which can carry

2299-588: Is based on the line state, and may be unidirectional (with each direction switching independently), or bidirectional (where the network elements at each end negotiate so that both directions are generally carried on the same pair of fibers). Canada Canada is a country in North America . Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into

2420-509: Is composed as follows: Data transmitted from end to end is referred to as path data . It is composed of two components: For STS-1, the payload is referred to as the synchronous payload envelope (SPE), which in turn has 18 stuffing bytes, leading to the STS-1 payload capacity of 756 bytes. The STS-1 payload is designed to carry a full PDH DS3 frame. When the DS3 enters a SONET network, path overhead

2541-527: Is considered a variation of SDH because of SDH's greater worldwide market penetration. SONET is subdivided into four sublayers with some factor such as the path, line, section and physical layer. The SDH standard was originally defined by the European Telecommunications Standards Institute (ETSI), and is formalised as International Telecommunication Union (ITU) standards G.707, G.783 , G.784, and G.803. The SONET standard

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2662-501: Is dictated by the bandwidth requirements for PCM-encoded telephonic voice signals: at this rate, an STS-1/OC-1 circuit can carry the bandwidth equivalent of a standard DS-3 channel, which can carry 672 64-kbit/s voice channels. In SONET, the STS-3c signal is composed of three multiplexed STS-1 signals; the STS-3c may be carried on an OC-3 signal. Some manufacturers also support the SDH equivalent of

2783-554: Is divided into 15 terrestrial and five marine ecozones . These ecozones encompass over 80,000 classified species of Canadian wildlife , with an equal number yet to be formally recognized or discovered. Although Canada has a low percentage of endemic species compared to other countries , due to human activities, invasive species , and environmental issues in the country , there are currently more than 800 species at risk of being lost . About 65 percent of Canada's resident species are considered "Secure". Over half of Canada's landscape

2904-517: Is exemplified by the IEEE 802.3 family of Media Independent Interfaces and the Optical Internetworking Forum family of System Packet Interfaces . Of these last two, the family of System Packet Interfaces is optimized to carry user packets from many channels. The family of System Packet Interfaces is the most important packet-oriented, chip-to-chip interface family used between devices in

3025-481: Is for path overhead; it is followed by the payload container, which can itself carry other containers. Administrative units can have any phase alignment within the STM frame, and this alignment is indicated by the pointer in row four. The section overhead (SOH) of a STM-1 signal is divided into two parts: the regenerator section overhead (RSOH) and the multiplex section overhead (MSOH). The overheads contain information from

3146-581: Is important when overhead bytes are added to incoming packets. PL-3 and SPI-3 were highly successful interfaces with many semiconductor devices produced to it. Synchronous Optical Network Synchronous Optical Networking ( SONET ) and Synchronous Digital Hierarchy ( SDH ) are standardized protocols that transfer multiple digital bit streams synchronously over optical fiber using lasers or highly coherent light from light-emitting diodes (LEDs). At low transmission rates data can also be transferred via an electrical interface. The method

3267-1019: Is intact and relatively free of human development. The boreal forest of Canada is considered to be the largest intact forest on Earth, with approximately 3,000,000 km (1,200,000 sq mi) undisturbed by roads, cities or industry. Since the end of the last glacial period , Canada has consisted of eight distinct forest regions . Approximately 12.1 percent of the nation's landmass and freshwater are conservation areas , including 11.4 percent designated as protected areas . Approximately 13.8 percent of its territorial waters are conserved, including 8.9 percent designated as protected areas. Canada's first National Park , Banff National Park established in 1885 spans 6,641 square kilometres (2,564 sq mi). Canada's oldest provincial park, Algonquin Provincial Park , established in 1893, covers an area of 7,653.45 square kilometres (2,955.01 sq mi). Lake Superior National Marine Conservation Area

3388-497: Is interleaved with it during transmission. Part of the overhead is transmitted, then part of the payload, then the next part of the overhead, then the next part of the payload, until the entire frame has been transmitted. In the case of an STS-1, the frame is 810 octets in size, while the STM-1/STS-3c frame is 2,430 octets in size. For STS-1, the frame is transmitted as three octets of overhead, followed by 87 octets of payload. This

3509-520: Is multiplexed by interleaving the bytes of the three STS-1 frames to form the STS-3 frame, containing 2,430 bytes and transmitted in 125  μs . Higher-speed circuits are formed by successively aggregating multiples of slower circuits, their speed always being immediately apparent from their designation. For example, four STS-3 or AU4 signals can be aggregated to form a 622.08 Mbit/s signal designated OC-12 or STM-4 . The highest rate commonly deployed

3630-590: Is one of the world's most ethnically diverse and multicultural nations, the product of large-scale immigration . Canada's long and complex relationship with the United States has had a significant impact on its history , economy , and culture . A developed country , Canada has a high nominal per capita income globally and its advanced economy ranks among the largest in the world by nominal GDP , relying chiefly upon its abundant natural resources and well-developed international trade networks . Recognized as

3751-408: Is repeated nine times, until 810 octets have been transmitted, taking 125  μs . In the case of an STS-3c/STM-1, which operates three times faster than an STS-1, nine octets of overhead are transmitted, followed by 261 octets of payload. This is also repeated nine times until 2,430 octets have been transmitted, also taking 125  μs . For both SONET and SDH, this is often represented by displaying

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3872-634: Is solely a federal responsibility and is uniform throughout Canada. Law enforcement, including criminal courts, is officially a provincial responsibility, conducted by provincial and municipal police forces. In most rural and some urban areas, policing responsibilities are contracted to the federal Royal Canadian Mounted Police . Canadian Aboriginal law provides certain constitutionally recognized rights to land and traditional practices for Indigenous groups in Canada. Various treaties and case laws were established to mediate relations between Europeans and many Indigenous peoples. The role of Aboriginal law and

3993-592: Is the OC-768 or STM-256 circuit, which operates at rate of just under 38.5 Gbit/s. Where fiber exhaustion is a concern, multiple SONET signals can be transported over multiple wavelengths on a single fiber pair by means of wavelength-division multiplexing , including dense wavelength-division multiplexing (DWDM) and coarse wavelength-division multiplexing (CWDM). DWDM circuits are the basis for all modern submarine communications cable systems and other long-haul circuits. Another type of high-speed data networking circuit

4114-533: Is the prime minister , who holds office by virtue of their ability to command the confidence of the elected House of Commons and is appointed by the governor general , representing the monarch of Canada , the ceremonial head of state . The country is a Commonwealth realm and is officially bilingual (English and French) in the federal jurisdiction. It is very highly ranked in international measurements of government transparency, quality of life, economic competitiveness, innovation, education and human rights. It

4235-453: Is the second-largest country . By land area alone, Canada ranks fourth , due to having the world's largest area of fresh water lakes . Stretching from the Atlantic Ocean in the east, along the Arctic Ocean to the north, and to the Pacific Ocean in the west, the country encompasses 9,984,670 km (3,855,100 sq mi) of territory. Canada also has vast maritime terrain, with

4356-407: Is the lowest SONET layer and it is responsible for transmitting the bits to the physical medium. The section layer is responsible for generating the proper STS-N frames which are to be transmitted across the physical medium. It deals with issues such as proper framing, error monitoring, section maintenance, and orderwire. The line layer ensures reliable transport of the payload and overhead generated by

4477-512: Is the source of sovereignty and authority in Canada. However, while the governor general or monarch may exercise their power without ministerial advice in rare crisis situations , the use of the executive powers (or royal prerogative ) is otherwise directed by the Cabinet , a committee of ministers of the Crown responsible to the elected House of Commons and chosen and headed by the prime minister,

4598-545: Is the world's largest freshwater protected area, spanning roughly 10,000 square kilometres (3,900 sq mi). Canada's largest national wildlife region is the Scott Islands Marine National Wildlife Area which spans 11,570.65 square kilometres (4,467.45 sq mi). Canada is described as a " full democracy ", with a tradition of liberalism , and an egalitarian , moderate political ideology. An emphasis on social justice has been

4719-444: Is transmitted in exactly 125  μs , therefore, there are 8,000 frames per second on a 155.52 Mbit/s OC-3 fiber-optic circuit. The STM-1 frame consists of overhead and pointers plus information payload. The first nine columns of each frame make up the section overhead and administrative unit pointers, and the last 261 columns make up the information payload. The pointers (H1, H2, H3 bytes) identify administrative units (AU) within

4840-644: The Canada Elections Act limits this to four years with a "fixed" election date in October; general elections still must be called by the governor general and can be triggered by either the advice of the prime minister or a lost confidence vote in the House. The 105 members of the Senate, whose seats are apportioned on a regional basis, serve until age 75. Canadian federalism divides government responsibilities between

4961-672: The Dominion Lands Act to regulate settlement and established the North-West Mounted Police to assert authority over the territory. This period of westward expansion and nation building resulted in the displacement of many Indigenous peoples of the Canadian Prairies to " Indian reserves ", clearing the way for ethnic European block settlements . This caused the collapse of the Plains Bison in western Canada and

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5082-407: The Arctic Ocean , making it the world's second-largest country by total area , with the world's longest coastline . Its border with the United States is the world's longest international land border. The country is characterized by a wide range of both meteorologic and geological regions. With a population of just over 41   million people, it has widely varying population densities, with

5203-746: The Battle of the Scheldt in 1944. Canada provided asylum for the Dutch monarchy while that country was occupied and is credited by the Netherlands for major contributions to its liberation from Nazi Germany . The Canadian economy boomed during the war as its industries manufactured military materiel for Canada, Britain, China , and the Soviet Union . Despite another Conscription Crisis in Quebec in 1944, Canada finished

5324-602: The COVID-19 pandemic in Canada began on January 27, 2020, with widespread social and economic disruption. In 2021, the possible graves of hundreds of Indigenous people were discovered near the former sites of Canadian Indian residential schools . Administered by various Christian churches and funded by the Canadian government from 1828 to 1997, these boarding schools attempted to assimilate Indigenous children into Euro-Canadian culture . By total area (including its waters), Canada

5445-571: The Canada Act 1982 , the patriation of Canada's constitution from the United Kingdom, concurrent with the creation of the Canadian Charter of Rights and Freedoms . Canada had established complete sovereignty as an independent country under its own monarchy . In 1999, Nunavut became Canada's third territory after a series of negotiations with the federal government. At the same time, Quebec underwent profound social and economic changes through

5566-783: The Canadian Shield , the interior plains , the Great Lakes-St. Lawrence Lowlands , the Appalachian region , the Western Cordillera , Hudson Bay Lowlands , and the Arctic Archipelago . Boreal forests prevail throughout the country, ice is prominent in northern Arctic regions and through the Rocky Mountains , and the relatively flat Canadian Prairies in the southwest facilitate productive agriculture. The Great Lakes feed

5687-554: The Constitution of Canada fully under Canadian control, referred only to Canada . Later that year, the name of the national holiday was changed from Dominion Day to Canada Day . The first inhabitants of North America are generally hypothesized to have migrated from Siberia by way of the Bering land bridge and arrived at least 14,000 years ago. The Paleo-Indian archeological sites at Old Crow Flats and Bluefish Caves are two of

5808-499: The First Nations , Inuit , and Métis , the last being of mixed descent who originated in the mid-17th century when First Nations people married European settlers and subsequently developed their own identity. The Indigenous population at the time of the first European settlements is estimated to have been between 200,000 and two million, with a figure of 500,000 accepted by Canada's Royal Commission on Aboriginal Peoples . As

5929-731: The Meech Lake Accord failed in 1990. This led to the formation of the Bloc Québécois in Quebec and the invigoration of the Reform Party of Canada in the West. A second referendum followed in 1995, in which sovereignty was rejected by a slimmer margin of 50.6 to 49.4 percent. In 1997, the Supreme Court ruled unilateral secession by a province would be unconstitutional, and the Clarity Act

6050-668: The Oka Crisis of 1990, the first of a number of violent confrontations between provincial governments and Indigenous groups. Canada joined the Gulf War in 1990 and was active in several peacekeeping missions in the 1990s, including operations in the Balkans during and after the Yugoslav Wars , and in Somalia , resulting in an incident that has been described as " the darkest era in the history of

6171-653: The Packet over SONET and Optical Transport Network , which are the principal protocols used to carry the internet between cities. It was designed to be used in systems that support OC-48 SONET interfaces . A typical application of PL-3 (SPI-3) is to connect a framer device to a network processor. It has been widely adopted by the high speed networking marketplace. The interface consists of (per direction): There are several clocking options. The interface operates around 100 MHz. Implementations of SPI-3 (PL-3) have been produced which allow somewhat higher clock rates. This

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6292-550: The Parliament of Canada and the commissioners represent the King in his federal Council , rather than the monarch directly. The powers flowing from the Constitution Act, 1867 , are divided between the federal government and the provincial governments to exercise exclusively and any changes to that arrangement require a constitutional amendment , while changes to the roles and powers of the territories may be performed unilaterally by

6413-539: The Quiet Revolution of the 1960s, giving birth to a secular nationalist movement. The radical Front de libération du Québec (FLQ) ignited the October Crisis with a series of bombings and kidnappings in 1970, and the sovereigntist Parti Québécois was elected in 1976, organizing an unsuccessful referendum on sovereignty-association in 1980. Attempts to accommodate Quebec nationalism constitutionally through

6534-662: The Saint Lawrence River as Canada . From the 16th to the early 18th century, Canada referred to the part of New France that lay along the Saint Lawrence River. Following the British conquest of New France , this area was known as the British Province of Quebec from 1763 to 1791. In 1791, the area became two British colonies called Upper Canada and Lower Canada . These two colonies were collectively named

6655-523: The St. Lawrence Iroquoian word kanata , meaning "village" or "settlement". In 1535, Indigenous inhabitants of the present-day Quebec City region used the word to direct French explorer Jacques Cartier to the village of Stadacona . Cartier later used the word Canada to refer not only to that particular village but to the entire area subject to Donnacona (the chief at Stadacona); by 1545, European books and maps had begun referring to this small region along

6776-758: The St. Lawrence River (in the southeast) where the lowlands host much of Canada's economic output. Canada has over 2,000,000 lakes—563 of which are larger than 100 km (39 sq mi)—containing much of the world's fresh water . There are also fresh-water glaciers in the Canadian Rockies , the Coast Mountains , and the Arctic Cordillera . Canada is geologically active , having many earthquakes and potentially active volcanoes . Average winter and summer high temperatures across Canada vary from region to region. Winters can be harsh in many parts of

6897-441: The head of government . To ensure the stability of government, the governor general will usually appoint as prime minister the individual who is the current leader of the political party that can obtain the confidence of a majority of members in the House. The Prime Minister's Office (PMO) is one of the most powerful institutions in government, initiating most legislation for parliamentary approval and selecting for appointment by

7018-568: The Atlantic coast. In general, early settlements during the Age of Discovery appear to have been short-lived due to a combination of the harsh climate, problems with navigating trade routes and competing outputs in Scandinavia. In 1583, Sir Humphrey Gilbert , by the royal prerogative of Queen Elizabeth I , founded St John's, Newfoundland , as the first North American English seasonal camp . In 1600,

7139-465: The Atlantic coast. As a consequence of various armed conflicts , France ceded nearly all of its colonies in North America in 1763. In 1867, with the union of three British North American colonies through Confederation , Canada was formed as a federal dominion of four provinces. This began an accretion of provinces and territories resulting in the displacement of Indigenous populations , and

7260-606: The Canadas until their union as the British Province of Canada in 1841. Upon Confederation in 1867 , Canada was adopted as the legal name for the new country at the London Conference and the word dominion was conferred as the country's title. By the 1950s, the term Dominion of Canada was no longer used by the United Kingdom, which considered Canada a "realm of the Commonwealth". The Canada Act 1982 , which brought

7381-466: The Canadian military ". Canada sent troops to Afghanistan in 2001 , resulting in the largest amount of Canadian deaths for any single military mission since the Korean War in the early 1950s. In 2011, Canadian forces participated in the NATO-led intervention into the Libyan Civil War and also became involved in battling the Islamic State insurgency in Iraq in the mid-2010s. The country celebrated its sesquicentennial in 2017, three years before

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7502-423: The Crown the governor general, lieutenant governors , senators, federal court judges, and heads of Crown corporations and government agencies. The leader of the party with the second-most seats usually becomes the leader of the Official Opposition and is part of an adversarial parliamentary system intended to keep the government in check. The Parliament of Canada passes all federal statute laws. It comprises

7623-439: The First Nations to education, government and legal rights. Because Britain still maintained control of Canada's foreign affairs under the British North America Act, 1867, its declaration of war in 1914 automatically brought Canada into the First World War . Volunteers sent to the Western Front later became part of the Canadian Corps , which played a substantial role in the Battle of Vimy Ridge and other major engagements of

7744-400: The French established their first seasonal trading post at Tadoussac along the Saint Lawrence. French explorer Samuel de Champlain arrived in 1603 and established the first permanent year-round European settlements at Port Royal (in 1605) and Quebec City (in 1608). Among the colonists of New France, Canadiens extensively settled the Saint Lawrence River valley and Acadians settled

7865-504: The LAN PHY variant encapsulates Ethernet data using 64B/66B line coding. However, 10 Gigabit Ethernet does not explicitly provide any interoperability at the bitstream level with other SDH/SONET systems. This differs from WDM system transponders, including both coarse and dense wavelength-division multiplexing systems (CWDM and DWDM) that currently support OC-192 SONET signals, which can normally support thin-SONET–framed 10 Gigabit Ethernet. User throughput must not deduct path overhead from

7986-411: The Métis' grievances ignited the Red River Rebellion and the creation of the province of Manitoba in July 1870. British Columbia and Vancouver Island (which had been united in 1866) joined the confederation in 1871 on the promise of a transcontinental railway extending to Victoria in the province within 10 years, while Prince Edward Island joined in 1873. In 1898, during the Klondike Gold Rush in

8107-414: The Northwest Territories, Parliament created the Yukon Territory. Alberta and Saskatchewan became provinces in 1905. Between 1871 and 1896, almost one quarter of the Canadian population emigrated south to the US. To open the West and encourage European immigration, the Government of Canada sponsored the construction of three transcontinental railways (including the Canadian Pacific Railway ), passed

8228-408: The Q3 interface protocol suite defined in ITU recommendations Q.811 and Q.812. With the convergence of SONET and SDH on switching matrix and network elements architecture, newer implementations have also offered TL1. Most SONET NEs have a limited number of management interfaces defined: To handle all of the possible management channels and signals, most modern network elements contain a router for

8349-427: The SDH/SONET frame structure and rate. This interleaving permits a very low latency for the encapsulated data. Data passing through equipment can be delayed by at most 32  microseconds  (μs), compared to a frame rate of 125 μs; many competing protocols buffer the data during such transits for at least one frame or packet before sending it on. Extra padding is allowed for the multiplexed data to move within

8470-408: The STS-1/OC-1, known as STM-0. In packet-oriented data transmission, such as Ethernet , a packet frame usually consists of a header and a payload . The header is transmitted first, followed by the payload (and possibly a trailer , such as a CRC ). In synchronous optical networking, this is modified slightly. The header is termed the overhead , and instead of being transmitted before the payload,

8591-458: The STS-3c is carried over OC-3, it is often colloquially referred to as OC-3c , but this is not an official designation within the SONET standard as there is no physical layer (i.e. optical) difference between an STS-3c and 3 STS-1s carried within an OC-3. SONET offers an additional basic unit of transmission, the STS-1 (Synchronous Transport Signal 1) or OC-1 , operating at 51.84 Mbit/s—exactly one third of an STM-1/STS-3c/OC-3c carrier. This speed

8712-682: The United Kingdom. The delay underscored Canada's independence. The first Canadian Army units arrived in Britain in December 1939. In all, over a million Canadians served in the armed forces during the Second World War . Canadian troops played important roles in many key battles of the war, including the failed 1942 Dieppe Raid , the Allied invasion of Italy , the Normandy landings , the Battle of Normandy , and

8833-617: The United States in 1846 ended the Oregon boundary dispute , extending the border westward along the 49th parallel . This paved the way for British colonies on Vancouver Island (1849) and in British Columbia (1858) . The Anglo-Russian Treaty of Saint Petersburg (1825) established the border along the Pacific coast, but, even after the US Alaska Purchase of 1867, disputes continued about

8954-466: The abortive Rebellions of 1837 . The Durham Report subsequently recommended responsible government and the assimilation of French Canadians into English culture. The Act of Union 1840 merged the Canadas into a united Province of Canada and responsible government was established for all provinces of British North America east of Lake Superior by 1855. The signing of the Oregon Treaty by Britain and

9075-566: The amount of buffering required between elements in the network. Both SONET and SDH can be used to encapsulate earlier digital transmission standards, such as the PDH standard, or they can be used to directly support either Asynchronous Transfer Mode (ATM) or so-called packet over SONET/SDH (POS) networking. Therefore, it is inaccurate to think of SDH or SONET as communications protocols in and of themselves; they are generic, all-purpose transport containers for moving both voice and data. The basic format of

9196-760: The centre of the political scale. Five parties had representatives elected to the Parliament in the 2021 election —the Liberals, who formed a minority government; the Conservatives, who became the Official Opposition ; the New Democratic Party (occupying the left ); the Bloc Québécois ; and the Green Party . Far-right and far-left politics have never been a prominent force in Canadian society. Canada has

9317-548: The constitution. The Supreme Court of Canada is the highest court, final arbiter, and has been led since 2017 by Richard Wagner , the Chief Justice of Canada . The governor general appoints the court's nine members on the advice of the prime minister and minister of justice . The federal Cabinet also appoints justices to superior courts in the provincial and territorial jurisdictions. Common law prevails everywhere except Quebec, where civil law predominates. Criminal law

9438-499: The country and consists of written text and unwritten conventions. The Constitution Act, 1867 (known as the British North America Act, 1867 prior to 1982), affirmed governance based on parliamentary precedent and divided powers between the federal and provincial governments. The Statute of Westminster, 1931 , granted full autonomy, and the Constitution Act, 1982 , ended all legislative ties to Britain, as well as adding

9559-421: The country, particularly in the interior and Prairie provinces, which experience a continental climate , where daily average temperatures are near −15  °C (5  °F ), but can drop below −40 °C (−40 °F) with severe wind chills . In non-coastal regions, snow can cover the ground for almost six months of the year, while in parts of the north snow can persist year-round. Coastal British Columbia has

9680-577: The early 1930s saw an economic downturn, leading to hardship across the country. In response to the downturn, the Co-operative Commonwealth Federation (CCF) in Saskatchewan introduced many elements of a welfare state (as pioneered by Tommy Douglas ) in the 1940s and 1950s. On the advice of Prime Minister William Lyon Mackenzie King , war with Germany was declared effective September 10, 1939, by King George VI , seven days after

9801-624: The emergence of a new Canadian identity , marked by the adoption of the maple leaf flag in 1965, the implementation of official bilingualism (English and French) in 1969, and the institution of official multiculturalism in 1971. Socially democratic programs were also instituted, such as Medicare , the Canada Pension Plan , and Canada Student Loans ; though, provincial governments, particularly Quebec and Alberta, opposed many of these as incursions into their jurisdictions. Finally, another series of constitutional conferences resulted in

9922-663: The exact demarcation of the Alaska–Yukon and Alaska–BC border. Following three constitutional conferences, the British North America Act, 1867 officially proclaimed Canadian Confederation on July 1, 1867, initially with four provinces: Ontario , Quebec, Nova Scotia, and New Brunswick. Canada assumed control of Rupert's Land and the North-Western Territory to form the Northwest Territories , where

10043-416: The federal government and the 10 provinces. Provincial legislatures are unicameral and operate in parliamentary fashion similar to the House of Commons. Canada's three territories also have legislatures, but these are not sovereign, have fewer constitutional responsibilities than the provinces, and differ structurally from their provincial counterparts. The Constitution of Canada is the supreme law of

10164-445: The first layer in the OSI networking model. The ATM and SDH layers are the regenerator section level, digital line level, transmission path level, virtual path level, and virtual channel level. The physical layer is modeled on three major entities: transmission path, digital line and the regenerator section. The regenerator section refers to the section and photonic layers. The photonic layer

10285-575: The frame graphically: as a block of 90 columns and nine rows for STS-1, and 270 columns and nine rows for STM1/STS-3c. This representation aligns all the overhead columns, so the overhead appears as a contiguous block, as does the payload. The internal structure of the overhead and payload within the frame differs slightly between SONET and SDH, and different terms are used in the standards to describe these structures. Their standards are extremely similar in implementation, making it easy to interoperate between SDH and SONET at any given bandwidth. In practice,

10406-515: The functionality of regenerators has been absorbed by the transponders of wavelength-division multiplexing systems. STS multiplexer and demultiplexer provide the interface between an electrical tributary network and the optical network. Add-drop multiplexers (ADMs) are the most common type of network elements. Traditional ADMs were designed to support one of the network architectures, though new generation systems can often support several architectures, sometimes simultaneously. ADMs traditionally have

10527-473: The growth of an independence movement in contrast to the Thirteen Colonies. The Proclamation and the Quebec Act in turn angered many residents of the Thirteen Colonies, further fuelling anti-British sentiment in the years prior to the American Revolution . After the successful American War of Independence, the 1783 Treaty of Paris recognized the independence of the newly formed United States and set

10648-416: The information payload. Thus, an OC-3 circuit can carry 150.336 Mbit/s of payload, after accounting for the overhead. Carried within the information payload, which has its own frame structure of nine rows and 261 columns, are administrative units identified by pointers. Also within the administrative unit are one or more virtual containers (VCs). VCs contain path overhead and VC payload. The first column

10769-466: The internal complex structure previously used to transport circuit-oriented connections was removed and replaced with a large and concatenated frame (such as STS-3c) into which ATM cells, IP packets, or Ethernet frames are placed. Both SDH and SONET are widely used today: SONET in the United States and Canada , and SDH in the rest of the world. Although the SONET standards were developed before SDH, it

10890-456: The introduction of European cattle farms and wheat fields dominating the land. The Indigenous peoples saw widespread famine and disease due to the loss of the bison and their traditional hunting lands. The federal government did provide emergency relief, on condition of the Indigenous peoples moving to the reserves. During this time, Canada introduced the Indian Act extending its control over

11011-515: The late 18th century, European Canadians forced Indigenous peoples to assimilate into a western Canadian society. Settler colonialism reached a climax in the late 19th and early 20th centuries. A period of redress began with the formation of a reconciliation commission by the Government of Canada in 2008. This included acknowledgment of cultural genocide , settlement agreements , and betterment of racial discrimination issues, such as addressing

11132-715: The later wars of the period constituted the North American theatre of the Seven Years' War . Mainland Nova Scotia came under British rule with the 1713 Treaty of Utrecht and Canada and most of New France came under British rule in 1763 after the Seven Years' War. The Royal Proclamation of 1763 established First Nation treaty rights, created the Province of Quebec out of New France, and annexed Cape Breton Island to Nova Scotia. St John's Island (now Prince Edward Island ) became

11253-761: The main front in the War of 1812 between the United States and the United Kingdom . Peace came in 1815; no boundaries were changed. Immigration resumed at a higher level, with over 960,000 arrivals from Britain between 1815 and 1850. New arrivals included refugees escaping the Great Irish Famine as well as Gaelic -speaking Scots displaced by the Highland Clearances . Infectious diseases killed between 25 and 33 percent of Europeans who immigrated to Canada before 1891. The desire for responsible government resulted in

11374-404: The majority residing in urban areas and large areas of the country being sparsely populated. Canada's capital is Ottawa and its three largest metropolitan areas are Toronto , Montreal , and Vancouver . Indigenous peoples have continuously inhabited what is now Canada for thousands of years. Beginning in the 16th century, British and French expeditions explored and later settled along

11495-672: The monarch, the House of Commons, and the Senate . While Canada inherited the British concept of parliamentary supremacy , this was later, with the enactment of the Constitution Act, 1982, all but completely superseded by the American notion of the supremacy of the law . Each of the 338 members of Parliament in the House of Commons is elected by simple plurality in an electoral district or riding. The Constitution Act, 1982 , requires that no more than five years pass between elections, although

11616-620: The name of Henry VII of England . In 1534, French explorer Jacques Cartier explored the Gulf of Saint Lawrence where, on July 24, he planted a 10-metre (33 ft) cross bearing the words, "long live the King of France", and took possession of the territory New France in the name of King Francis I . The early 16th century saw European mariners with navigational techniques pioneered by the Basque and Portuguese establish seasonal whaling and fishing outposts along

11737-461: The network commands and underlying (data) protocols. With advances in SONET and SDH chipsets, the traditional categories of network elements are no longer distinct. Nevertheless, as network architectures have remained relatively constant, even newer equipment (including multi-service provisioning platforms ) can be examined in light of the architectures they will support. Thus, there is value in viewing new, as well as traditional, equipment in terms of

11858-439: The older categories. Traditional regenerators terminate the section overhead, but not the line or path. Regenerators extend long-haul routes in a way similar to most regenerators, by converting an optical signal that has already traveled a long distance into electrical format and then retransmitting a regenerated high-power signal. Since the late 1990s, regenerators have been largely replaced by optical amplifiers . Also, some of

11979-430: The oldest sites of human habitation in Canada. The characteristics of Indigenous societies included permanent settlements, agriculture, complex societal hierarchies, and trading networks. Some of these cultures had collapsed by the time European explorers arrived in the late 15th and early 16th centuries and have only been discovered through archeological investigations. Indigenous peoples in present-day Canada include

12100-488: The overall framing, as the data is clocked at a different rate than the frame rate. The protocol is made more complex by the decision to permit this padding at most levels of the multiplexing structure, but it improves all-around performance. The basic unit of framing in SDH is a STM-1 (Synchronous Transport Module, level 1), which operates at 155.520 megabits per second (Mbit/s). SONET refers to this basic unit as an STS-3c (Synchronous Transport Signal 3, concatenated). When

12221-638: The path layer. It provides synchronization and multiplexing for multiple paths. It modifies overhead bits relating to quality control. The path layer is SONET's highest level layer. It takes data to be transmitted and transforms them into signals required by the line layer, and adds or modifies the path overhead bits for performance monitoring and protection switching. Network management systems are used to configure and monitor SDH and SONET equipment either locally or remotely. The systems consist of three essential parts, covered later in more detail: The main functions of network management thereby include: Consider

12342-613: The payload bandwidth, but path-overhead bandwidth is variable based on the types of cross-connects built across the optical system. Note that the data-rate progression starts at 155 Mbit/s and increases by multiples of four. The only exception is OC-24, which is standardized in ANSI T1.105, but not a SDH standard rate in ITU-T G.707. Other rates, such as OC-9, OC-18, OC-36, OC-96, and OC-1536, are defined but not commonly deployed; most are considered orphaned rates. The physical layer refers to

12463-552: The permafrost is uncertain because the Arctic has been warming at three times the global average as a result of climate change in Canada . Canada's annual average temperature over land has risen by 1.7 °C (3.1 °F), with changes ranging from 1.1 to 2.3 °C (2.0 to 4.1 °F) in various regions, since 1948. The rate of warming has been higher across the North and in the Prairies. In

12584-548: The plight of missing and murdered Indigenous women . It is believed that the first documented European to explore the east coast of Canada was Norse explorer Leif Erikson . In approximately 1000 AD, the Norse built a small short-lived encampment that was occupied sporadically for perhaps 20 years at L'Anse aux Meadows on the northern tip of Newfoundland . No further European exploration occurred until 1497, when seafarer John Cabot explored and claimed Canada's Atlantic coast in

12705-704: The present-day Maritimes , while fur traders and Catholic missionaries explored the Great Lakes , Hudson Bay , and the Mississippi watershed to Louisiana . The Beaver Wars broke out in the mid-17th century over control of the North American fur trade. The English established additional settlements in Newfoundland in 1610 along with settlements in the Thirteen Colonies to the south. A series of four wars erupted in colonial North America between 1689 and 1763;

12826-488: The provinces collect more revenue than the federal government, equalization payments are made by the federal government to ensure reasonably uniform standards of services and taxation are kept between the richer and poorer provinces. The major difference between a Canadian province and a territory is that provinces receive their sovereignty from the Crown and power and authority from the Constitution Act, 1867 , whereas territorial governments have powers delegated to them by

12947-807: The rights they support were reaffirmed by section 35 of the Constitution Act, 1982 . These rights may include provision of services, such as healthcare through the Indian Health Transfer Policy , and exemption from taxation. Canada is a federation composed of 10 federated states , called provinces, and three federal territories . These may be grouped into four main regions : Western Canada , Central Canada , Atlantic Canada , and Northern Canada ( Eastern Canada refers to Central Canada and Atlantic Canada together). Provinces and territories have responsibility for social programs such as healthcare , education , and social programs , as well as administration of justice (but not criminal law). Although

13068-740: The southeast. Canada is also home to the world's northernmost settlement, Canadian Forces Station Alert , on the northern tip of Ellesmere Island —latitude 82.5°N—which lies 817 kilometres (508 mi) from the North Pole. In latitude, Canada's most northerly point of land is Cape Columbia in Nunavut at 83°6′41″N, with its southern extreme at Middle Island in Lake Erie at 41°40′53″N. In longitude, Canada's land extends from Cape Spear , Newfoundland, at 52°37'W, to Mount St. Elias , Yukon Territory, at 141°W. Canada can be divided into seven physiographic regions:

13189-485: The southern regions of Canada, air pollution from both Canada and the United States—caused by metal smelting, burning coal to power utilities, and vehicle emissions—has resulted in acid rain , which has severely impacted waterways, forest growth, and agricultural productivity. Canada is one of the largest greenhouse gas emitters globally , with emissions increased by 16.5 percent between 1990 and 2022. Canada

13310-447: The terms STS-1 and OC-1 are sometimes used interchangeably, though the OC designation refers to the signal in its optical form. It is therefore incorrect to say that an OC-3 contains 3 OC-1s: an OC-3 can be said to contain 3 STS-1s. The Synchronous Transport Module, level 1 (STM-1) frame is the basic transmission format for SDH—the first level of the synchronous digital hierarchy. The STM-1 frame

13431-498: The terms of peace, ceding British North American territories south of the Great Lakes and east of the Mississippi River to the new country. The American war of independence also caused a large out-migration of Loyalists , the settlers who had fought against American independence. Many moved to Canada, particularly Atlantic Canada, where their arrival changed the demographic distribution of the existing territories. New Brunswick

13552-512: The three parts defined above: This will often consist of software running on a Workstation covering a number of SDH/SONET network elements SONET equipment is often managed with the TL1 protocol. TL1 is a telecom language for managing and reconfiguring SONET network elements. The command language used by a SONET network element, such as TL1, must be carried by other management protocols, such as SNMP , CORBA , or XML . SDH has been mainly managed using

13673-406: The transmission system itself, which is used for a wide range of management functions, such as monitoring transmission quality, detecting failures, managing alarms, data communication channels, service channels, etc. The STM frame is continuous and is transmitted in a serial fashion: byte-by-byte, row-by-row. The transport overhead is used for signaling and measuring transmission error rates , and

13794-532: The war with a large army and strong economy. The financial crisis of the Great Depression led the Dominion of Newfoundland to relinquish responsible government in 1934 and become a Crown colony ruled by a British governor. After two referendums , Newfoundlanders voted to join Canada in 1949 as a province. Canada's post-war economic growth, combined with the policies of successive Liberal governments, led to

13915-534: The war. The Conscription Crisis of 1917 erupted when the Unionist Cabinet's proposal to augment the military's dwindling number of active members with conscription was met with vehement objections from French-speaking Quebecers. In 1919, Canada joined the League of Nations independently of Britain, and the Statute of Westminster, 1931 , affirmed Canada's independence. The Great Depression in Canada during

14036-459: The world's longest coastline of 243,042 kilometres (151,019 mi). In addition to sharing the world's largest land border with the United States —spanning 8,891 km (5,525 mi) —Canada shares a land border with Greenland (and hence the Kingdom of Denmark ) to the northeast, on Hans Island , and a maritime boundary with France 's overseas collectivity of Saint Pierre and Miquelon to

14157-524: Was defined by Telcordia and American National Standards Institute (ANSI) standard T1.105. which define the set of transmission formats and transmission rates in the range above 51.840 Mbit/s. SDH differs from Plesiochronous Digital Hierarchy (PDH) in that the exact rates that are used to transport the data on SONET/SDH are tightly synchronized across the entire network, using atomic clocks . This synchronization system allows entire inter-country networks to operate synchronously, greatly reducing

14278-602: Was developed to replace the plesiochronous digital hierarchy (PDH) system for transporting large amounts of telephone calls and data traffic over the same fiber without the problems of synchronization. SONET and SDH, which are essentially the same, were originally designed to transport circuit mode communications (e.g., DS1 , DS3 ) from a variety of different sources, but they were primarily designed to support real-time, uncompressed, circuit-switched voice encoded in PCM format. The primary difficulty in doing this prior to SONET/SDH

14399-676: Was in turn split from Nova Scotia as part of a reorganization of Loyalist settlements in the Maritimes, which led to the incorporation of Saint John, New Brunswick , as Canada's first city. To accommodate the influx of English-speaking Loyalists in Central Canada, the Constitutional Act of 1791 divided the province of Canada into French-speaking Lower Canada (later Quebec ) and English-speaking Upper Canada (later Ontario ), granting each its own elected legislative assembly. The Canadas were

14520-430: Was passed by Parliament, outlining the terms of a negotiated departure from Confederation. In addition to the issues of Quebec sovereignty, a number of crises shook Canadian society in the late 1980s and early 1990s. These included the explosion of Air India Flight 182 in 1985, the largest mass murder in Canadian history; the École Polytechnique massacre in 1989, a university shooting targeting female students; and

14641-408: Was that the synchronization sources of these various circuits were different. This meant that each circuit was actually operating at a slightly different rate and with different phase. SONET/SDH allowed for the simultaneous transport of many different circuits of differing origin within a single framing protocol. SONET/SDH is not a complete communications protocol in itself, but a transport protocol (not

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