From: Radoslav Vasilev (deckland@gmail.com)
Date: Fri Jun 16 2006 - 05:16:19 ART
Hi Group,
In IE Lab 6, task 8.3 I'm supposed to configure QoS on Cisco 3550 on an
outgoint port connecting a wireless access point.
The task is simple - because of pure VoIP quality, make sure the CoS=5
frames are services from the expedite queue (port is fastethernet) and all
the other CoS are serviced from the best-effort outgoing queue.
Solution is simple:
mls qos
int fa0/16
wrr-queue cos-map 1 0 1 2 3 4 6 7
wrr-queue cos-map 4 5
priority-queue out
As the switch is Layer 3 at the same time, in reality all the traffic going
to the wireless stations will come from a routed switch port:
O IA 191.1.177.0 [110/848] via 191.1.48.4, 1d22h, GigabitEthernet1/0/4
C 191.1.48.0 is directly connected, GigabitEthernet1/0/4
O IA 191.1.45.0 [110/1001] via 191.1.48.4, 4d15h, GigabitEthernet1/0/4
O IA 191.1.34.0 [110/65] via 191.1.48.4, 4d15h, GigabitEthernet1/0/4
O IA 191.1.27.0 [110/847] via 191.1.48.4, 1d22h, GigabitEthernet1/0/4
O IA 191.1.23.0 [110/846] via 191.1.48.4, 4d15h, GigabitEthernet1/0/4
O IA 191.1.13.0 [110/974] via 191.1.48.4, 4d15h, GigabitEthernet1/0/4
O IA 191.1.7.0 [110/848] via 191.1.48.4, 1d22h, GigabitEthernet1/0/4
O IA 191.1.5.0 [110/911] via 191.1.48.4, 1d22h, GigabitEthernet1/0/4
O IA 191.1.125.0 [110/910] via 191.1.48.4, 4d15h, GigabitEthernet1/0/4
O IA 191.1.77.0 [110/848] via 191.1.48.4, 1d22h, GigabitEthernet1/0/4
[...]
It's obvious the only port from where traffic will ever come from is gi
1/0/4 (sorry but i have only 3750s in my lab)
So, in reality, my Cos=5 to priority-egress-queue on fa 0/16 will never take
effect, as I'm (by default) resetting Cos from the routed port to Cos=0.
The question is should i at least do:
int gi 1/0/14
mls qos trust dscp
so DSCP are trusted and Cos is mapped by the default dscp-to-cos map?
Is it a mistake if i don't do this in the lab, knowing from the begining
that my fa0/16 configuration will never kick in?
Or in other words - how is addiotional configuration graded in the lab?
Rado
This archive was generated by hypermail 2.1.4 : Sat Jul 01 2006 - 07:57:33 ART