3Com CoreBuilder 7000, Operation Manual, Page: 53 / 264

3
E-IISP P
ROTOCOL
This chapter provides basic concepts and information about:
Introducing Enhanced Interim InterSwitch Protocol (E-IISP)
IISP vs. E-IISP
Hierarchy in an E-IISP Network
Planning a Network with E-IISP
E-IISP Hierarchical Routing Algorithm
Introducing
Enhanced Interim
InterSwitch
Protocol (E-IISP)
E-IISP is a 3Com proprietary hop-by-hop dynamic routing protocol. It was
developed as an improvement to the ATM Forum IISP standard. E-IISP
defines a protocol for
dynamic updates of the topology database in each
switch. This enables the switch to automatically learn the addresses of
other switches and end stations attached to them. In addition, the
CoreBuilder 7000 family ATM switch employs a proprietary hierarchical
routing algorithm (see “Routing — Internal Links” on page 125). This
hierarchical routing algorithm requires that the network be connected in
a hierarchical topology, along with an addressing scheme similar to that
used in telephone networks.
IISP vs. E-IISP
The IISP routing protocol is a simple, universal protocol used to connect
the CoreBuilder 7000 family ATM switch to ATM switches of other
vendors.
IISP (PNNI phase 0) is the first phase standard for multiple switch
networks. This protocol defines the routing decision/algorithm according
to a
static database. You create the database manually via management
and build it in a hierarchical structure. The routing decision is based upon
address matching, full or partial, using the best match method.