Atm Traffic Management Support; Network Ingress Classification; Atm Access Egress Queuing And Shaping; Control Word - Alcatel-Lucent 7705 Service Manual

ATM Traffic Management Support

The 7705 SAR supports the ATM Forum Traffic Management Specification Version 4.1.

Network Ingress Classification

Classification is based on the EXP value of the pseudowire label and EXP-to-FC mapping is
determined by the network ingress QoS policy.
The ingress MPLS packets are mapped to forwarding classes based on EXP bits that are part
of the headers in the MPLS packets. The EXP bits are used to ensure an end-to-end QoS
application. For PW services, there are two labels: one for the MPLS tunnel and one for the
pseudowire itself. Mapping is done according to the outer tunnel EXP bit settings. This
ensures that if the EXP bit settings are altered along the path by the intermediate LSR nodes,
the newly requested FC selection is carried out properly.
Ingress GRE and IP packets are mapped to forwarding classes based on DSCP bit settings of
the IP header.

ATM Access Egress Queuing and Shaping

The 7705 SAR provides a per-SAP queuing architecture on the T1/E1 ASAP Adapter card
and OC3/STM1 Clear Channel Adapter card. After the ATM pseudowire is terminated at the
access egress point, all the ATM cells are mapped to default queue 1, and queuing is
performed on a per-SAP basis.
Access ingress and access egress traffic management features are identical for SAP-to-SAP
and SAP-to-SDP applications. For more information on ATM access egress queuing and
scheduling, refer to the 7705 SAR OS Quality of Service Guide.

Control Word

ATM VLL supports an optional control word (CW). Refer to
page 190
7705 SAR OS Services Guide
for more information.
VLL Services
Pseudowire Control Word on
Page 139