E-Series Priority Queuing (Ieee 802.1Q) - Cisco ONS 15454 SDH Configuration Manual

Chapter 23 E-Series and G-Series Ethernet Operation
network. The entry and egress ports on the ONS network must be set to Tagged for this process to occur.
Example 2 in
with a Q-tag.
For more information about setting ports to Tagged and Untag, refer to the Cisco ONS 15454 Procedure
Guide or the Cisco ONS 15454 SDH Procedure Guide.
Caution ONS nodes propagate VLANs whenever a node appears on the network view of another node, regardless
of whether the nodes are in the same SONET/SDH network or connect through DCC. For example, if
two ONS nodes without DCC connectivity belong to the same login node group, VLANs propagate
between the two ONS nodes. VLAN propagation happens even though the ONS nodes do not belong to
the same SONET/SDH ring.

E-Series Priority Queuing (IEEE 802.1Q)

Networks without priority queuing handle all packets on a first-in-first-out (FIFO) basis. Priority
queuing reduces the impact of network congestion by mapping Ethernet traffic to different priority
levels. The E-Series card supports priority queuing. The E-Series card maps the eight priorities specified
in IEEE 802.1Q to two queues, low priority and high priority
Table 23-3
User Priority
0,1,2,3
4,5,6,7
Q-tags carry priority queuing information through the network
Figure 23-15 illustrates the handling of packets that both enter and exit the ONS network
Priority Queuing
Queue
Low
High
Cisco ONS 15454 and Cisco ONS 15454 SDH Ethernet Card Software Feature and Configuration Guide, R8.0
Allocated Bandwidth
30%
70%
E-Series Priority Queuing (IEEE 802.1Q)
(Table 23-3).
(Figure 23-16).
23-19