What if there is no Vlan for voice but you use a switchport SEE My example - HELP

What if you find a remote office site with a vpn router and he has the Cisco phones plugged into the router and on the lan switch on the 881 you see no qos tagging. but of course their is DSCP shaping done with a policy map on the wan interface going OUT.

I want to add a switch because they need more than 4 ports. So I am going to create the vlans on the new switch and TRUNK to the router and leave the vlan interface on their for the 1 subnet they use for both phones and workstations.

CONCERN: do I even setup qos on the switch and turn on mls qos? don't I need to allow dscp values on the trunk to the router? can anyone help me? what do I setup for qos on the switch to then hand off DSCP values via the trunk. I have no clue here.

interface FastEthernet0/3
description Standard Cisco IP Phone and Workstation Port
switchport access vlan 176
switchport mode dynamic desirable
no logging event link-status
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
priority-queue out
auto qos voip cisco-phone
spanning-tree portfast

interface FastEthernet0/3
description Standard Cisco IP Phone and Workstation Port
switchport access vlan 789
switchport mode dynamic desirable
switchport voice vlan 41
no logging event link-status
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
mls qos trust device cisco-phone
mls qos trust cos
auto qos voip cisco-phone
spanning-tree portfast

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Comments

networker050184

What have you found through your research so far? Give us what you are thinking and we can tell you if you're going in the right direction. Or if you want someone to do it for you I'm sure they'll be happy to for a small consulting fee!

itdaddy

I really have little experience with qos and voice setup. I guess I can setup a data vlan and a voice vlan myself. I kind of get it and probably can do that. I just don't understand cisco enough to see how the remote site can use no vlan for both data and voice and only use 1 vlan for both then how can you use QQS if you only have 1 vlan? I have read of vlan 0 but I am not sure how it all works. I understand COS to DSCP mapping and why L2 to L3 etc..but I have no experience with this stuff in Route switch you dont get alot of this stuff. I can probably make a data vlan and make this correct. I was only trying to understand how does it work without QOS or is it working on some level..thanks anyways. I wasnt asking you to do it for me just help me understand cisco phones. I have seen cos 3 and cos5 coming from cisco and I am only use to Mitel phones and only 1 COS value. So just some understanding of how it works. Thank you.

Jollycork

Users get really crappy phone service, if it works at all, and that is "if" they can understand someone on the other end.

yes you should have data on it's own Vlan and Phones on their own. There's no reason for data such as internet traffic from users computers to go over the phone LAN.

Legacy User

Eh..phone quality really depends on the user count and available bandwidth. If for example at the remote site there are 2 people/2 phones running that config with a fair amount of bandwidth available then they probably will not notice any difference then compared to if it was a larger user base with that same config. Do your research so you can tune that branch site for optimized performance. If provider allows qos do it all the way through from access layer to internet edge.

One reason you would segment voice vlan and data is that you keep the voice traffic separate from the data traffic. If both networks (data,voice) share the same vlan which means they all share the same subnet then some smart guy can run a packet sniffer and extract the voice traffic which means someone can possibly download your voice conversation. The reason why data and voice can work on the same vlan or subnet because voice is just traffic, same way how data is traffic. If from that data vlan the phones can communicate with the CUCM or wherever else they register to than it'll still work. The phones will work with or without being in a voice vlan. Its just a security measure and best practice to segment that traffic.

If you see a lot of issues with the remote site. Make a design plan, present the observations and plan of action to whoever needs to know. Than take action. Remember no one knows everything but you have to be resourceful!

itdaddy

thank you guys for your help sounds great.