Ilmi; Vpi/Vci Address Ranges - Juniper JUNOSE SOFTWARE 11.0.X - LINK LAYER CONFIGURATION GUIDE 4-1-2010 Configuration Manual

If you are upgrading to the current JUNOSe software release from a lower-numbered
release, configurations that use CAC and bulk configuration on the same ATM interface
continue to work. However, we recommend that you disable CAC on these ATM
interfaces to ensure continued compatibility with future JUNOSe releases.
For information about how to use the atm cac command to configure CAC, see
"Setting Optional Parameters" on page 24. For information about how to use the
atm bulk-config command to create a bulk-configured VC range, see "Bulk
Configuration of VC Ranges" on page 581 in "Configuring Dynamic Interfaces Using
Bulk Configuration" on page 573.

ILMI

ATM interfaces support the ATM Forum integrated local management interface (ILMI),
versions 3.0, 3.1, and 4.0. An important feature of ILMI is the ability to poll or send
keepalive messages across the UNI. ATM interfaces always respond to such messages,
which are sent by an ATM peer device. Optionally, you can configure ATM major
interfaces to generate keepalive messages, a process that enables a continuous
ATM-layer connectivity verification; if the ATM peer stops responding to keepalive
messages, the router disables the ATM interface.
The ATM interface is not reenabled until the keepalive message's responses are
received (or until the keepalive feature is disabled on the ATM port). To enable ILMI
and control the generation of keepalive messages, use the atm ilmi-enable and atm
ilmi-keepalive commands.

VPI/VCI Address Ranges

The VPI/VCI address ranges allowed on ATM interfaces are module dependent. Certain
modules on ERX14xx models, ERX7xx models, or the Juniper Networks ERX310
Broadband Services Router have a fixed allocation scheme, whereas others have a
configurable allocation scheme. In the configurable allocation scheme, a bit range is
shared across the VPI and VCI fields.
For example, if an ATM interface has a bit range of 18, and 4 bits are allocated to
the VPI space, then 14 bits are left for the VCI space. The resulting numeric range is
0 to 2n-1, where n is the number of bits for each space. Completing the example, if
4 bits were allocated for the VPI space and 14 for the VCI space, the configurable
range would be 0 to 15 for VPI and 0 to 16,383 for the VCI space. To configure the
bit range, use "atm vc-per-vp" on page 31 .
See "Supported Features" on page 12 for details on how various line module and
I/O modules support configurable VPI/VCI address ranges.
NOTE: The E120 and E320 routers support the full VPI/VCI address range; therefore,
it has a fixed allocation scheme.
Chapter 1: Configuring ATM
9
Overview