QOS VOIP - Hosted IP PBX Provider

Discussion in 'Cisco' started by pilotnine, Jul 4, 2008.

  1. pilotnine

    pilotnine Guest

    Hi,

    Cisco 1720 router with 1 internet T1 to a IP PBX hosted provider.
    I am having constant dropped calls, choppy, echoes, backup noises and
    clipped calls when using the IP phone. I would like to implement QOS
    on router, and am wondering if this will help. Hosted provider is
    using MGCP and g.721 compression. The T1 line is mostly idle and used
    very little for anything other than web surfing and phone calls.T1
    line is error free and IP PBX provider checked and claim nothing is
    wrong on their end.

    Does anyone have a sample QOS configuration that may work? or point me
    to the right direction where I may obtain
    more information.


    IP hosted PBX provider -----Internet Cloud -----Cisco 1720---
    Firewall-------Switch---SIP IP phones..

    Cisco IOS Software, C1700 Software (C1700-ENTBASE-M), Version
    12.3(8)T11, RELEASE SOFTWARE (fc1)
    Technical Support: http://www.cisco.com/techsupport
    Copyright (c) 1986-2005 by Cisco Systems, Inc.
    Compiled Wed 10-Aug-05 19:07 by dchih

    ROM: System Bootstrap, Version 12.2(7r)XM1, RELEASE SOFTWARE (fc1)


    Thanks!

    Bill
     
    pilotnine, Jul 4, 2008
    #1
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  2. pilotnine

    bill the kid Guest



    Mike,

    Thank you for your suggestion. Do you have a URL or the author of the
    mentioned doc - "Here is a great document on all
    aspects of QoS on Cisco devices (it's "best practices" for Quality of
    Service). "

    Thanks!

    Bill
     
    bill the kid, Jul 4, 2008
    #2
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  3. pilotnine

    John Osmon Guest

    wrote:
    : Hi,

    : Cisco 1720 router with 1 internet T1 to a IP PBX hosted provider.
    : I am having constant dropped calls, choppy, echoes, backup noises and
    : clipped calls when using the IP phone. I would like to implement QOS
    : on router, and am wondering if this will help.

    Don't forget -- QOS on your 1720 only queues things on the egress of
    your network. Your provider has to provide queuing for the ingress.

    A better solution is to buy a bigger pipe, but that isn't always
    an economical solution.

    I sell a hosted PBX product. We try to make sure we also sell the
    Internet access so that we can control packet flow to the customer
    premise. It helps us eliminate a number of the quality issues that
    other hosted companies run into.

    We also keep all of our VOIP gear in a single /24, so that customers can
    prioritize packets in our direction based on IP address. A lot of cheap
    equipment allows you to priority-queue things based on IP addresses.
    (Actiontec ADSL equipment comes to mind...)

    An old-school Cisco template for priority queueing would look like:
    !
    interface Serial0
    priority-group 1
    !
    access-list 112 permit ip any <voiop-ip-block> <mask>
    !
    priority-list 1 protocol ip high list 112

    This template is likely to work on your 1720 -- but doesn't use the
    newer modular QOS mechanisms, so is likely to draw ire from many
    directions.
     
    John Osmon, Jul 8, 2008
    #3
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