Chapter 8 Permanent Virtual Connections (PVCs and PVPs)
102 Avaya M770 ATM Switch User’s Guide
Note: Before you attempt to set up a PVC you will need to reduce the signalling VCI
range, for a virtual port, that is used for SVCs.
Do not use a VCI in the range [0...31] as these are reserved by the ATM Forum. To
reduce the VCI range, see Setting Virtual Port Parameters in Chapter 6 Managing
Virtual Ports.
Since a VCL is bi-directional, a traffic descriptor needs to be defined for the transmit
and receive data paths belonging to the VCL. For VCL A, the traffic descriptor for
the receive data path at port B should be the same as the traffic descriptor for the
transmit data path at port A. Similarly, the traffic descriptor for the transmit data
path at port B should be the same as the traffic descriptor for the receive data path at
port A. For more information about managing traffic descriptors, see Managing
Traffic Descriptors later in this chapter.
Creating a PVC connection
PVC connections will be re-established automatically when the M770 ATM Switch
powers up. You can have up to 1k (1024) PVC connections on a module.
Creating a Point-to-Point (PP) PVC connection
To set up a PP PVC with uni-directional traffic on one module, you must set up a bi-
directional PP PVC that has a Peak Cell Rate (PCR) of zero in one direction. To set
up a bi-directional PVC between 2 ports on different modules (on the same switch)
you must type the command on the CLI of each module.The appropriate order of
the VCL and the td1, td2 should switch places (rx-td in one module should be the tx-
td in the other module).
The command described below will setup a VCL on each <slot.port.vpi.vci> and a
PVC connection joining the two. The PVC connection will be automatically assigned
an id.
Traffic descriptors do not have to be specified. If they are not, UBR traffic will be
assumed and an existing UBR traffic descriptor will be used. If no such traffic
descriptor exists, one will be automatically set up for UBR traffic. If any other type
of traffic is required, you must first set up the traffic descriptors in the usual way
(using the command td setup). on the required modules.
If one of the specified VCLs already exists, this VCL’s traffic descriptors will be used
in preference to any other VCLs specified by the user. If both VCLs already exist,
their traffic descriptors must be compatible (that is the transmit and receive traffic
descriptor identifiers) for the command to succeed.