View source for Reliable User Datagram Protocol

{{Short description|Internet protocol}}
{{confused|Reliable Data Protocol}}
{{more footnotes|date=June 2013}}
{{Internet protocol suite|transport=[[Reliable User Datagram Protocol|RUDP]]}}
In [[computer network]]ing, the '''Reliable User Datagram Protocol''' ('''RUDP''') is a [[transport layer]] [[Communications protocol|protocol]] designed at [[Bell Labs]] for the [[Plan 9 from Bell Labs|Plan 9]] [[operating system]]. It aims to provide a solution where [[User Datagram Protocol|UDP]] is too primitive because guaranteed-order [[packet (information technology)|packet]] delivery is desirable, but [[Transmission Control Protocol|TCP]] adds too much complexity/overhead. In order for RUDP to gain higher [[Quality of service requirements|quality of service]], RUDP implements features that are similar to TCP with less overhead.
==Implementations==
In order to ensure quality, it extends UDP by means of adding the following features:
# Acknowledgment of received packets
# Windowing and [[flow control (data)|flow control]]
# Retransmission of lost packets
# Over buffering (Faster than real-time streaming)
RUDP is not currently a formal standard, however it was described in an [[IETF Internet Draft]] in 1999.<ref>[https://datatracker.ietf.org/doc/html/draft-ietf-sigtran-reliable-udp-00/ Reliable UDP Protocol]</ref> It has not been proposed for standardization.
==Cisco RUDP==
[[Cisco]] in its Signalling Link Terminals (either standalone or integrated in another gateway) uses RUDP for [[backhaul (telecommunications)|backhauling]] of [[Signaling System 7|SS7]] MTP3 or [[ISDN]] signaling.
# RUDP v0 (no checksums) is used for SS7 MTP3 backhaul.
# RUDP v1 (with checksum) is used for ISDN PRI backhaul.
The versions are mutually incompatible and differ slightly from the IETF draft.{{Citation needed|date=March 2016}} The structure of the Cisco Session Manager used on top of RUDP is also different.
==Microsoft R-UDP==
Microsoft introduced another protocol which it named R-UDP and used it in its MediaRoom product (now owned by Ericsson) for IPTV service delivery over multicast networks.  This is a proprietary protocol and very little is known about its operation.  It is not thought to be based on the above referenced IETF draft.<ref>{{Cite web|url=http://www.viavisolutions.com/sites/default/files/technical-library-files/mstvtest_an_tfs_tm_ae.pdf|title=Microsoft TV Test document by JDSU}}</ref>
==See also==
* [[Stream Control Transmission Protocol]]
* [[Datagram Transport Layer Security]]
==References==
{{Reflist}}
==External links==
* [https://9p.io/sources/plan9/sys/src/9/ip/rudp.c Plan 9 implementation of RUDP]
* https://datatracker.ietf.org/doc/html/draft-ietf-sigtran-reliable-udp-00/
* [http://www.cisco.com/en/US/products/hw/vcallcon/ps2152/products_data_sheet09186a0080091b58.html Cisco Signaling Link Terminal]
[[Category:Transport layer protocols]]
[[Category:Internet protocols]]