Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors

Voice + Data Problem, Need Help

Viewing 12 posts - 1 through 12 (of 12 total)
  • Author
  • #24245

    I am having a VOIP Device(Cisco) for testing purpose. The problem I am facing is that when I use both acessing internet & make a call through the VOIP at a time, I am geting disturbance in the voice, voice is being cut. So, is there any solution for this like any applications or tools that can help me stop using internet, while making a call automatically. Please help.


    Your trouble is lack of bandwith.You do not have enough “pipe” for voice and data at the same time.
    I own some Quintum A200 and on those there is a setting that lower the ammount of bandwith used by the computer when there is a voice call in progress, releasing all the bandwith to to the P.C. when the call is over.
    The only trouble: The minimun that you could set the bandwith is 64 kb.
    In my case ,I am using ADSL that is 64 kb both ways (very cheap). for that reason it does not work for me.
    I read something about bandwith reservations when you use Cisco routers, but have not idea if it is related to your trouble or not.

    Good luck!!!


    Even I do have a 64 kbps leased line.


    1. Does it happen on the LAN-LAN VOIP or Internet VOIP ?

    Might want to Seperate your voice and data on VLANS on the local side and create QOS/ class of service profiles on the wan side


    No, the scenario is different here, its not on the LAN-LAN VOIP, but the Internet VOIP. Our LAN is connected to the Internet through a 64kbps leased line.


    Well there is your problem.
    If you have 64k line without compression for voice than as soon you start a call (64K) your data transmission will be cut our the other way around.
    At least you need 128k and Q&S on your router.
    The only i know of who can do this is the Cisco 1751V or if you have a vpn wan connection to a high-end Cisco voice enabled router you could use a 836 or 837 in stealt modus


    Does that mean the CISCO ATA 186 I am using doesn’t support compression?? Is there any other way such that I can use the same Cisco-ATA-186 with compression?? Is there any website so that I can get a clear idea for these kinds of Scenario??

    noname to Paul

    Yes your ATA 186 will do VOIP with compression. Most likely it it doing it already.
    The trouble is that with only 64 kb, any aplication that you try to “share” on the same pipe with voip will take all the existing bandwith, not leaving enough for the ATA to provide a good quality call.
    If you have good routers, you should be able to make what is call “bandwith reservations” on a intranet to make the voice trafic a priority over normal data.
    But when you go to the internet over that narrow bridge (64 kb) your data will bump your voice over the rail and into the water bellow.
    You could do only so much with such a low bandwith.


    make a QoS policy such as custom queue or the like for your voip device on your router.

    Teodor Georgiev

    Cisco ATA-186 also do support G.723 (5.3 and 6.3Kbit) and G.729A.

    With G.723 you definitely will be able to have more than 5 calls over a 64Kbit link. ANother question is how good is that 64Kbit and is it a dedicated one 🙂


    If Cisco ATA-186 supports G.723 (5.3 and 6.3Kbit) and G.729A then, could u tell me where do I enable it or how is the process that I can implement that compression? There was no manual with this device.


    Still I didn’t get a clear idea of using compression of voice in VOIP devices. If anyone can help me out plz.
    One more problem is that I have an ADSL connection now with 128 kbps, but during night the BW is abruptly reeducing to around 32kbps, and the provider demands that from his end it is perfectly giving 128kbps, but from my end I am able to get only 32kbps, and this starts at eve 7:00PM till morn 7:00 AM. Any suggestions plz to find out where is the actual BW loss. There is no physical or logical change in any of the settings I use during thee time slots.

Viewing 12 posts - 1 through 12 (of 12 total)
  • The forum ‘Voice over IP’ is closed to new topics and replies.