Basic QoS question

[jono]

Hello one and all,

Have the following qos question which I am having trouble understanding...

First off, let me state my purpose: What im trying to acheive is to QoS tag VoIP traffic from the ISP entering the router interface as EF so we can do internal QoS on the clients internal switches - the incoming traffic from the ISP has no qos markings.

The setup so far:

Have setup a rule to tag incoming VoIP traffic (101110 = DSCP 46) on a particular interface on a router. Something like this:

VoIP LAN traffic into -> fa0/1 -> outgoing VoIP traffic tagged and prioritised and delivered to the ISP (fa0/1 is the interface that links to the ISP)

My question is will this port fa0/1 also tag WAN traffic received back from my ISP? - so does my incoming rule on fa0/1 tag both incoming traffic from the LAN side and incoming traffic from the WAN side? Or should I look at tagging incoming traffic from the ISP elsewhere like on fa1/1 which is the trunk to the switch...

Thanks,

Jono Bedford

Auckland, New Zealand.

[Tom Watts]

Hi Jono, what switch?

The small business switches are ingress only.

-Tom

[jono]

Hi Thomas,

The router is a 1841

the switch is a SGE2000P

Thanks,

Jono.

[Tom Watts · Accepted solution]

The behavior of the switch, in Basic QoS will trust already mark traffic and mark only ingress traffic. So if an egress mark from the router, the switch trusts it. If no mark from the router, the traffic will get mark on the ingress port of the switch.

-Tom