The 9.4.2 version manual at chapter 14.3 “Priority on vlans (802.1P)” says:
"VLAN settings can also cause the module to convert received non-VLAN packets into
VLAN packets. In this case, the 802.1p priority in packets leaving the module is set to the
priority established by the DiffServ configuration."
DiffServ sets the priority level (0 to 7) to code points (from 0 to 63); according to what (see above) says the manual, it seams that the code points in the DiffServe page are intended to be vlans when the vlan page of the SM is setted to tag out going packets.
Is this right ?
If yes, there is a discrepancy in the number of possible vlans (4094) and possible code points (64), why is that ?
If no, how can I assign priority level to a vlan that is tagged by the SM ?
Steven
The DSCP mapping section is actually for tying together 802.1p CoS and IP DSCP marks. Specifically, if a frame with no 802.1p arrives, it will automatically classify it based on the DSCP set within the IP packet so that layer 2 devices know how to prioritize the traffic. This requires it to add an 802.1p header to the ethernet frame. What the manual is referring to, though, is that 802.1p and 802.1q go hand-in-hand. Ethernet CoS is only available with VLANs. So if you have some traffic coming in on VLAN 96 that has DSCP 40 and priority enabled, the Canopy system will automatically set CoS 5 based on that mapping. Because it cannot strip this CoS marking, the frame will egress with VLAN 96/CoS 5 even if you’ve configured the SM to have VLAN 96 as the untagged VLAN.
Hope this helps