Is this QOS configuration really doing what we want it to?

[Stephen_Stormon]

Our VoIP phones send traffic with a DSCP value of 46. The phones are connected to a Summit X440-G2 stack in a VLAN called "VoIP" that has the following settings configured:

Slot-1 Summit-RV-VoIP.2 # show diffserv examination
CodePoint->QOSProfile mapping:
00->QP1 01->QP1 02->QP1 03->QP1 04->QP1 05->QP1 06->QP1 07->QP1
08->QP2 09*>QP1 10->QP2 11*>QP1 12->QP2 13*>QP1 14->QP2 15*>QP1
16->QP3 17*>QP1 18->QP3 19*>QP1 20->QP3 21*>QP1 22->QP3 23*>QP1
24->QP4 25*>QP1 26->QP4 27*>QP1 28->QP4 29*>QP1 30->QP4 31*>QP1
32->QP5 33*>QP1 34->QP5 35*>QP1 36->QP5 37*>QP1 38->QP5 39*>QP1
40*>QP1 41*>QP1 42*>QP1 43*>QP1 44*>QP1 45*>QP1 46->QP6 47*>QP1
48*>QP8 49*>QP1 50*>QP1 51*>QP1 52*>QP1 53*>QP1 54*>QP1 55*>QP1
56->QP8 57->QP8 58->QP8 59->QP8 60->QP8 61->QP8 62->QP8 63->QP8

Slot-1 Summit-RV-VoIP.4 # show diffserv replacement
QOSProfile->CodePoint mapping:
QP1 -> 00
QP2 *> 10
QP3 -> 16
QP4 *> 26
QP5 *> 34
QP6 *> 46
QP8 *> 48

enable diffserv examination port 1:2 (one of the ports a phone is connected to)

The exact same settings are configured on the core switch at our location, and on the core switch in the data center where the VoIP server is located.

My understanding is that by "enabling diffserv examination", the switch will look at traffic coming into the port, see that it is tagged with DSCP 46, and assign that traffic to QP6, which will be the priority used to the destination.

Do we need to "disable dot1p examination" on all ports? Would a better way be to assign QP6 to the entire VoIP VLAN?

[Stephen_Stormon]

We have our switches connected to XMC and I am wondering if the message I received when I attempted to disable dot1p is related to that. if so, what is the proper way to disable dot1p examination?

Summit-RV-Core.1 # disable dot1p examination ports all
WARNING: The dot1p examination status was configured via network management which requires dot1p replacement on all ports.
Do you want to overwrite the network management configuration? (y/N)

[Patrick_Voss]

Dot1p examination should be the only one enabled by default. If you would like to be sure you can disable both. The diffserv command is the correct command to enable for all ports.

[Stephen_Stormon]

So we should run "disable dot1p examination ports all" and "disable dot1p replacement ports all" in order to then just use the values that we have defined with diffserv and "enable diifserv examination ports all", correct?

[Patrick_Voss]

Hello Stephen,

Dot1p takes precedence over difsserv. You will need to disable it before diffserv will start working.

diffserv would be a better way to apply QOS then using the entire VLAN.