Who has the million dollar answer!
We have a mysterious issue... or mayb not to some :)
Our packets of voice are tagged with voice all the way along our network..until..it hits the data vlan then its gone! if we have a voice vlan instead on that interface then theres no issues what so ever, browny points to the winner :))
dan u desicrption not details
but i can guess u are losing the qos marking when the vlan get routed or in other word when going from L2 to L3
check the following
u need to have trust cos on the switch port level on the voice vlans
onthe switch uplink ports(port from switch to switch and from switch to router including trunks as well) u need to rust DSCP
this way u will preserve the qos marking
try it and let me know
this is called trust boundaries
if helpful Rate
We have the trust cos on all the switch port levels and trunks etc. and at the switch level that connects we have trust dscp already... strange.
Some clarifying questions:
You say that your voice packets are tagged with voice all the way along the network. How are you verifying this and do you mean both the COS and the DSCP bits?
If I remeber correctly, the IP phone only sets the COS priority (IP Precedence or 802.1p). It is left to the first hop L3 device to translate that IP Precedence to a DSCP setting. And to set the IP Precedence in the frame on the next subnet, as the original frame (the one sent from the IP phone) is lost at the router.
Obviously, if the voice traffic to moving from a voice VLAN to a data VLAN, it is being routed at L3. Do you have multiple voice VLANs and does the QOS setting survive moving from one voice VLAN to another?
Hiya sorry for the delay was off on holiday :)
To clarify.. the DSCP is tagged all the way along
I have checked and the qos dies when it hits any data vlan.
Hope this helps :)
first i wish u had a nice holyday
ok now i thing the view is getting more clear
can u tell me which commands u use to check the qos along the way
and u mean that port is connected to the router that connected to the 3750?
if this is the case
can u tell me what qos config if on the 3750
like marking, trust, cos/dscp-map on the port base
and u have the intevaln routing on that switch as well ?
thank you thank you :)
we just used wireshark along the way in conjunction with the monitor session command.
yes thats correct :)
its all auto mls qos etc, and it has trust DSCP. i also turned off the auto rewrite mls qos but still to no avail.
yes inter :)
i know this is not the ideal way bit try
to make PBR
policy based routing apply it on the data vlan interface i mean the SVI vlan interface
that match any traffic sourced from voice vlan going to any
and set the action to mak the dscp to EF
access-list 100 permit udp [voice vlan IP ]any range 16384 32767
match access-group 100
set ip dscp EF
and apply it in the inbound direction on the SVI
and let me know
OR if u want better way
make the switch port as truk and trust DSCP
on the router make it trunk and make two subinterfaces one in voice vlan and the other in data vlan
make the link fron ur switch to the router as routed port
in this way u will route the traffic as it passing a router interface from ur switch
becuase logicaly u dont need to take the voice traffic over data in the same vlan
becuase the idea is to separate them logicaly
in ur network along way till the exit point
and as u see at that point u have the problem