Setup QoS without VLANs

[brianhssllc]

I have a situation with a stack of 8 3Com 4500's where there are softphone users experiencing voice quality problems. There are no VLANs or QoS currently in place.

The softphones have an option to tag traffic as DSCP 46, which according to 3com documentation is "Expedited Forwarding (EF) class: In this class, packets can be forwarded regardless of link share of other traffic. The class is suitable for preferential services with low delay, low packet loss ratio, low jitter, and assured bandwidth"

My question is what needs to be enabled on the switches to do this? (I doubt that DSCP priorization would just happen automatically without setting some sort of QoS.)

The 3com documentation is a bit sparse but it appears that I need to:
- set priority trust on each port so that the DSCP packet priority level takes precedence over port priority
- set SP or WFQ queue scheduling on each port

Does that seem accurate or am I missing something?

 

[cknipe]

how many phones are you running in your network?

whats the ip/subnet address on the single subnet you have the phones on?

 

[VinceWhirlwind]

Do you have hardware IP phones as well?

Softphones are more likely to experience problems as a result of contended CPU, etc.. resources on the PC itself than on the network.