asked on

Cisco VoIP QoS

Hi,

I have configured QoS on my Cisco 1721 for VoIP - the only problem is, it is only working for the outbound side of the call. So the person I call can hear me perfectly (QoS is working), but I cannot hear them very clearly when someone downloads something on the internet (QoS isn't working). I have enabled a "service-policy outbound VoIP-QoS" on the dialer, however I cannot seem to do it as "service-policy inbound VoIP-QoS" I get an error when I try to apply that. Does anyone have any ideas how to fix this?

Thanks

Mark

netman42

Mark,
What size pipes are you using between sites and are you doing anything with your provider as far as prioritizing the voice traffic? Are you using Diff-Serv to mark the expedited voice traffic? Can you post a portion of the config so we can take a look at it?

Thanks,
Netman42

mark_06

ASKER

Hi,
I am using 512k (sym) DSL pipes bonded, its the fastest we can get. I have asked the ISP to pritoritise the voice traffic, whether they have or not, or at least as of yet. I am marking all the rtp audio packets with"dscp ef" on its way out. I am also using nbar, to detect the packets.

Here is the relevant config:
!
class-map match-any VoIP
match protocol rtp audio
!
!
policy-map VoIP-QoS
class VoIP
priority percent 70
set dscp ef
class class-default
fair-queue
!
!
!
interface Dialer3
bandwidth 512
ip address negotiated
no ip proxy-arp
ip nbar protocol-discovery
ip load-sharing per-packet
ip nat outside
ip virtual-reassembly
encapsulation ppp
load-interval 30
dialer pool 3
dialer-group 3
no cdp enable
ppp authentication chap callin
service-policy output VoIP-QoS
!
interface Dialer4
bandwidth 512
ip address negotiated
no ip proxy-arp
ip nbar protocol-discovery
ip load-sharing per-packet
ip nat outside
ip virtual-reassembly
encapsulation ppp
no ip mroute-cache
load-interval 30
dialer pool 4
dialer-group 4
no cdp enable
ppp authentication chap callin
service-policy output VoIP-QoS

netman42

In my case, to ensure that I was marking traffic, I had to use a sniffer and capture the traffic from phone switch to phone switch to make sure that EF gets marked all the way through. Often times, I would find where I left out a switch port or something with no QOS configured. Does your phone switch initiate any way to mark packets as EF right out of the switch? If not, does your switch configs have qos applied to the ports where your phone equipment is? What is the size of the stream you are paying for with the ISP's CAR?

Thanks,
Netman42

benhanson

This is generally referred to as One way voice, have you checked out Cisco's troubleshooting doc for this?

http://www.cisco.com/warp/public/788/AVVID/fix_1way_voice.html

A bit dense, I know . . .

benhanson

Sorry, it's late and I misread your question. Ignore that post!

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benhanson

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mark_06

ASKER

Hi,
Sorry for not posting - i am still waiting on the ISP to confirm the QoS on their side, they are being a real pain!
Is the way I am doing the QoS from my end ok? or should I do it a different way?
Thanks
Mark

mark_06

ASKER

BTW - I am running asterisk as my VoIP System.