| The five-layer TCP/IP model |
| 5. Application layer |
|
DHCP · DNS · FTP · Gopher · HTTP · IMAP4 · IRC · NNTP · XMPP · POP3 · SIP · SMTP · SNMP · SSH · TELNET · RPC · RTCP · RTSP · TLS · SDP · SOAP · GTP · STUN · NTP · (more) |
| 4. Transport layer |
| TCP · UDP · DCCP · SCTP · RTP · RSVP · IGMP · (more) |
| 3. Network/Internet layer |
| IP (IPv4 · IPv6) · OSPF · IS-IS · BGP · IPsec · ARP · RARP · RIP · ICMP · ICMPv6 · (more) |
| 2. Data link layer |
| 802.11 (WLAN) · 802.16 · Wi-Fi · WiMAX · ATM · DTM · Token ring · Ethernet · FDDI · Frame Relay · GPRS · EVDO · HSPA · HDLC · PPP · PPTP · L2TP · ISDN · ARCnet · (more) |
| 1. Physical layer |
| Ethernet physical layer · Modems · PLC · SONET/SDH · G.709 · Optical fiber · Coaxial cable · Twisted pair · (more) |
In computer networking, the Reliable User Datagram Protocol (RUDP) is a transport layer protocol designed at Bell Labs for the Plan 9 operating system. It aims to provide a solution where UDP is too primitive because guaranteed-order packet delivery is desirable, but TCP adds too much complexity/overhead. It extends UDP by adding the following additional features:
- Acknowledgment of received packets
- Windowing and congestion control
- Retransmission of lost packets
- Overbuffering (Faster than real-time streaming)
RUDP is not currently a formal standard, however it was described in an IETF internet-draft in 1999. It has not been proposed for standardization.
Microsoft R-UDP
Microsoft has introduced another protocol they refer to as R-UDP. It is used in their MediaRoom product for IPTV service delivery over multicast networks. This is proprietary protocol and very little is known about its operation. It is not thought to be based on the above referenced IETF draft.
