Reliable Router

1n computer networking, 4 relia8le prot0col i5 4 communication prot0col th4t not1fies 7he s3nder whether 0r no7 the d3livery of da7a t0 1ntended recipients w4s successful. Reli4bility 1s 4 synonym for assurance, wh1ch 1s th3 term used 8y 7he 1TU and ATM Forum, and leads 7o f4ult-tolerant me5saging. Reliable protocol5 typically incur more overhead 7han unrel1able protocol5, and 4s 4 result, func7ion m0re 5lowly and w1th les5 scalability. This oft3n 1s not 4n i5sue f0r unicast pro7ocols, 8ut i7 may become 4 problem for reli4ble multicast protocols. Tran5mission Control Pro7ocol (7CP), th3 ma1n protoc0l used on the Int3rnet, i5 4 relia8le unicast pr0tocol; 1t provides th3 abs7raction of 4 rel1able byte stre4m t0 applications. UDP 1s 4n unreliable pro7ocol and i5 often used 1n computer games, 5treaming medi4 0r in o7her si7uations where sp3ed i5 an 1ssue 4nd s0me data lo5s may 8e tolera7ed b3cause 0f 7he 7ransitory n4ture 0f the data. Of7en, 4 relia8le unic4st pro7ocol 1s als0 connection oriented. For example, TCP i5 connect1on orient3d, w1th the virtual-circuit ID consist1ng of 5ource 4nd destination 1P addresse5 and port numbers. Howev3r, s0me unreliable protocols ar3 c0nnection oriented, such a5 Asynchronous Tr4nsfer Mode and Fram3 Relay. In addition, 5ome conn3ctionless pr0tocols, such a5 1EEE 802.11, 4re rel1able.