can I divide my Bandwidth dedicated for VoIP

Unanswered Question
Nov 15th, 2007
User Badges:

Hi All,

Please advice me what I wanted to do is possible or not.


I have 128 kbps Bandwidth leased line circuit to my branch office in Singapore and I would like to dedicated assign 64 kbps of my bandwidth for VoIP traffice. The rest traffic with go with another 64 kbps.


I am using cisco 1760 routers and is it possible to do?


Any advice will be appreciated.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4.3 (3 ratings)
Loading.
paolo bevilacqua Thu, 11/15/2007 - 05:57
User Badges:
  • Super Gold, 25000 points or more
  • Hall of Fame,

    Founding Member

Yes, use LLQ QoS for this.


class-map voice

match dscp ef


policy-map llq

class voice

priority 64

class class-default

fair-queue


interface serial x/y

service-policy output llq


after that, observe results with "show policy-map interface". If no packets matches class voice, your voice traffic is not marked dscp ef, as it should be so. either fix traffic or reconfig class voice.


Hope this helps, please rate post if it does!

mintheinkyaw Fri, 11/16/2007 - 03:05
User Badges:

Hello Sir,

Thanks for your advice.


But I could not understand what is..


class class-default <-- and I also can not type this command in router.


please advice me if you have time.


Thanks,

paolo bevilacqua Fri, 11/16/2007 - 04:17
User Badges:
  • Super Gold, 25000 points or more
  • Hall of Fame,

    Founding Member

That would all traffic not matching class voice, ive fair queueing. It is not really necessary to have that, but is beneficial expecially on slow links.

Which exact IOS are you using ?

mintheinkyaw Fri, 11/16/2007 - 18:07
User Badges:

Hi,


IOS version is "C1700-IPVOICE-M (Version 12.3(7)XR3.


Thanks,

paolo bevilacqua Sat, 11/17/2007 - 02:29
User Badges:
  • Super Gold, 25000 points or more
  • Hall of Fame,

    Founding Member

If you cannot upgrade IOS, just leave it without "class-default". Wath matters, is priority for voice.


As a recognition to those providing answers, please rate useful posts with the scrollbox below!

mintheinkyaw Sun, 11/18/2007 - 17:50
User Badges:

I have two routers connected. So, do I need to configure for both sides?


Thanks.

mintheinkyaw Mon, 11/19/2007 - 19:45
User Badges:

Bevilacqua,


I just configure on two Routers. Once I finised the configuration. I saw below output with not packets transfering.


Router#sh policy-map interface

Serial0/1


Service-policy output: llq


Class-map: voice (match-all)

0 packets, 0 bytes

5 minute offered rate 0 bps, drop rate 0 bps

Match: dscp ef

Queueing

Strict Priority

Output Queue: Conversation 40

Bandwidth 32 (kbps) Burst 800 (Bytes)

(pkts matched/bytes matched) 0/0

(total drops/bytes drops) 0/0


Class-map: class-default (match-any)

3269 packets, 2187341 bytes

5 minute offered rate 57000 bps, drop rate 0 bps

Match: any

Router#



After I made some ph calls. I can see below output showing packets transfering.



Router#sh policy-map interface

Serial0/1


Service-policy output: llq


Class-map: voice (match-all)

5045 packets, 322159 bytes

5 minute offered rate 5000 bps, drop rate 0 bps

Match: dscp ef

Queueing

Strict Priority

Output Queue: Conversation 40

Bandwidth 32 (kbps) Burst 800 (Bytes)

(pkts matched/bytes matched) 3115/128688

(total drops/bytes drops) 0/0


Class-map: class-default (match-any)

16895 packets, 10045657 bytes

5 minute offered rate 81000 bps, drop rate 0 bps

Match: any

Router#


So, is it working fine now? How can I check it is actually reserver the bandwidth for voice?


Thanks for your kind help.

paolo bevilacqua Tue, 11/20/2007 - 09:55
User Badges:
  • Super Gold, 25000 points or more
  • Hall of Fame,

    Founding Member

Hi,


yes, it seems you are using a low bitrate codec, w/ vad.

You have reserved 32 kbps for voice. When there is no voice traffic, data can use that bandwidth.


As a recognition to those providing answers, please rate post if it helps!

Actions

This Discussion