Appendix F Routing and Signalling Concepts
Avaya M770 ATM Switch User’s Guide 303
For example, 2.1.1 represents a virtual port number of 1, on physical port number 1
on module number 2. Root virtual ports are all assigned with an identifier of 0.
For more information about managing virtual ports, see Managing Virtual Ports in
Chapter 6.
ILMIThe M770 ATM Switch supports ILMI and several signalling protocols.
ILMI is used between an end-station and a switch for the following:
• Automatic configuration of signalling and port parameters
• Address registration.
Setting up SVCsThe M770 ATM Switch supports UNI 3.0, 3.1 and 4.0 signalling for connection setup
between an end-station and a switch. IISP and PNNI 1.0 signalling are used for
inter-switch connection.
When a connection setup request is transmitted by an end-station using the UNI
signalling protocol, the M770 ATM Switch will use the ATM address of the called
party and look up the longest matching addresses in its internal routing table.
If there is more than one longest matching address, it selects the appropriate port to
route in terms of meeting the CoS and QoS requirements, and the minimum
cumulative Administrative Weight of the links on the path to the destination.
Once the preferred output port has been determined, the setup request is forwarded
to that port. Each switch forwards the connection setup request in the same manner,
until the destination end-station is reached. If the destination end-station agrees to
accept the connection, a SVC is set up.
Figure F.2 Signalling through the switches
Endstation 1
vpi,vci
vpi,vci
vpi,vci
Endstation 2
Avaya M770
ATM Switch #1
Avaya M770
ATM Switch #2