Lag On Access - Alcatel-Lucent 7750 SR OS Interface Configuration Manual

LAG

LAG on Access

Link Aggregation Groups (LAG) is supported on access ports. This is treated the same as LAG on
network ports which provides a standard method to aggregate Ethernet links. The difference lies in
how QoS is handled. If all members of the LAG are on the same IOMCFM then there is no
difference in how HQoS is handled. For example, for routed packets or for VPLS known unicast,
hashing is performed to get an ECMP value and then rehashed to do the spraying for the access
LAG ports. SAP to SAP VLL, and VPLS flooded packets will only use one port of the LAG.
There are two user-selectable modes to address the need to manage an HQoS policy on a SAP (this
can include a link aggregate which spans cards).
1. Divide the SLA among the IOMs, based on their share of the LAG group. For example, a
2. All ports get the full SLA. With the example above, each port would get a PIR of 100
The following features are supported as an extension of lsr-load-balancing lbl-ip.
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100 Mb PIR with 2 links on IOM A and 3 links on IOM B, IOM A would get 40 Mb PIR
and IOM B would get a 60 MB PIR. The advantage of this method is that the overall
SLA can be enforced. The disadvantage is a single flow cannot exceed the IOM's share
of the SLA. This is the default method.
Mb. The advantage of this method is a single flow can consume the entire SLA. The
disadvantage is that the overall SLA can be exceeded if the flows span multiple ports.
Supported on the IOM-3 and as well as the IOM-2 (mode C) and IOM-1 (mode B)
Supported for IPv4 and as well as for IPv6 (IPv6 works only on IOM-3 chassis mode D)
lsr-load-balancing lbl-ip can be enabled in the config>router>interface context.
7750 SR OS Interface Configuration Guide