13-34
Cisco ONS 15454 Reference Manual, R7.0
78-17191-01
Chapter 13 Management Network Connectivity
13.7 13.7.4 OSI Routing
Figure 13-21 OSI Main Setup
This address is also the Router 1 primary manual area address, which is viewed and edited on the
Provisioning > OSI > Routers subtab. See the “13.7.7 OSI Virtual Routers” section on page 13-41 for
information about the OSI router and manual area addresses in CTC.
13.7.4 OSI Routing
OSI architecture includes ESs and ISs. The OSI routing scheme includes:
• A set of routing protocols that allow ESs and ISs to collect and distribute the information necessary
to determine routes. Protocols include the ES-IS and IS-IS protocols. ES-IS routing establishes
connectivity and reach ability among ESs and ISs attached to the same (single) subnetwork.
• A routing information base (RIB) (see containing this information, from which routes between ESs
can be computed. The RIB consists of a table of entries that identify a destination (for example, an
NSAP), the subnetwork over which packets should be forwarded to reach that destination, and a
routing metric. The routing metric communicates characteristics of the route (such as delay
properties or expected error rate) that are used to evaluate the suitability of a route compared to
another route with different properties, for transporting a particular packet or class of packets.
• A routing algorithm, Shortest Path First (SPF), that uses information contained in the RIB to derive
routes between ESs.