QoS and voice signaling on TCCS interconnection

[rdubo]

Hello,

I try to connect 2 PBX using Transparent Clear Channel Signaling. It works!! Now I want to implement Qos for it.

We use a frame-relay link. I want to know which way is the best to use: LLQ or frame relay ip rtp priority?

How can we match the voice-signaling in order to make a voice-signaling class?

Is it enough if we put the ip precedence 5 on the dial peer interface in order to tag the voice packets? (voice + signaling)

Thank you

[fbahram]

QoS depends on your network setup and also on your IOS. LLQ works far better than IP RTP PRIORITY and gives you much more flexibility. IP precedence 5 on all voip peers should be added but is not sufficient to guarantee voice delivery prior to data so LLQ or some other method is a must along with FRTS (Frame Relay Traffic Shaping). Below is a URL with sample configs on LLQ and FR:

You can modify the class-maps to define any class of traffic to be prioritized and be sure not to allocate more than 75% of the link bandwidth at all times.

http://www.cisco.com/warp/customer/788/voice-qos/voip-ov-fr-qos.html

Look under LLQ (above)

------

You can add this CLI for voice signaling, define a new access-list 102 so you have:

access-list 102 permit udp any any range 16384 37276

access-list 102 permit tcp any any eq 1720

!

since signaling for H323 is on TCP port 1720 this should cover it. Rest of configs is the same as URL.

Hope this helps.

[rdubo]

Actually, here is the configuration

______ _____ _____ _____

| PBX |---E1-----| 7200 |-----Frame Relay 2 Mbps-----| 7200 |--E1-----| PBX |

The voice packets come from the PBX , not from a LAN.

Why the "ip precedence 5" won't be sufficient?

What is the bandwidth necessary for the voice signaling? I calculate that I need:

30 x 12kbps (for voice channels with CRTP) + 80kbps (for voice sig)

Am I completely wrong?

Do you think a configuration like that will be good?

class-map voice

match access-group 101

!

access-list 101 permit udp any any range 16384 32767

access-list 101 permit tcp any any eq 1720

access-list 101 permit ip any any precedence 5

!

policy-map mypolicy

class voice

priority 440

class class-default

fair-queue

!

interface Serial1/0.1 point-to-point

ip address....

frame-relay ip rtp header-compression

frame-relay interface-dlci 100

class voipFR

!

map-class frame-relay voipFR

no frame-relay adaptive-shaping

frame-relay cir 1920000

frame-relay mincir 192000

frame-relay bc 1920

service-policy output mypolicy

dial-peer voice 2 voip

destination-pattern 6000

session target ipv4:192.168.10.1

ip precedence 5

....

Thank you for you help