IBM BC-203 manual Rsrb, BC-204

Overview of IBM Networking

RSRB

Note All commands supported on the Cisco 7500 series routers are also supported on the

Cisco 7000 series routers.

RSRB

In contrast to Source-Route Bridging (SRB), which involves bridging between Token Ring media only, RSRB is Cisco’s first technique for connecting Token Ring networks over non-Token Ring network segments. (DLSw+ is Cisco’s strategic method for providing this function.)

Cisco’s RSRB software implementation includes the following features:

•Provides for multiple routers separated by non-Token Ring segments. Three options are available:

–Encapsulate the Token Ring traffic inside IP datagrams passed over a Transmission Control Protocol (TCP) connection between two routers.

–Use Fast-Sequenced Transport (FST) to transport RSRB packets to their peers without TCP or User Datagram Protocol (UDP) header or processor overhead.

–Use data link layer encapsulations over a single serial line, Ethernet, Token Ring, or Fiber Distributed Data Interface (FDDI) ring connected between two routers attached to Token Ring networks.

•Provides for configurable limits to the size of the TCP backup queue.

Figure 85 shows an RSRB topology. The virtual ring can extend across any non-Token Ring media supported by RSRB, such as serial, Ethernet, FDDI, and WANs. The type of media you select determines the way you set up RSRB.

Figure 85 RSRB Topology

	Virtual ring
Token	Non-Token Ring
Ring	Media
Token	Token
Ring	Ring

Token

Ring

S2327

Note If you bridge across Token Ring media, it is recommended that you do not use RSRB. Use SRB instead. Refer to the chapter “Configuring Source-Route Bridging.”

Cisco IOS Bridging and IBM Networking Configuration Guide

BC-204