Inter-region iLBC codec negotions

I am working through the lab and have set up Branch2 and CorpHQ region for the use of iLBC. I have set the link type to Lossy but still see G729 as the negotiated codec. Is this expected?

Mike

Comments

  •  

    What Kind/Type of phones are you using? Do they support iLBC at all?

  • From the rack rentals - 7961's
    Best Regards,

    Mike Lydick





    On Tue, Apr 3, 2012 at 4:09 AM, datoc <[email protected]> wrote:

     

    What Kind/Type of phones are you using? Do they support iLBC at all?




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  • 7961 does not support iLBC.

  • Hi Mike, 

     

    if you are using the same phone as INE has on rack rentals, which is Cisco IP Phone 7961G, only support G711u and G729a as per the datasheet for this model. The iLBC on this example was asked only for configurations purpose. To test it you may use 7965G.

     

    VoiceInsider

    Kind Regards 

  • This is exactly correct. A 7962 would also suffice. The configuration was simply so that you are aware of the procedure, and that many students have their own, different phones. 



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    On Apr 4, 2012, at 17:11, Voiceinsider <[email protected]> wrote:

    Hi Mike, 

     

    if you are using the same phone as INE has on rack rentals, which is Cisco IP Phone 7961G, only support G711u and G729a as per the datasheet for this model. The iLBC on this example was asked only for configurations purpose. To test it you may use 7965G.

     

    VoiceInsider

    Kind Regards 




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  • The major advantage of iLBC codec is the fact that it allows a noticeable
    improvement in voice quality especially in IP networks. Beside this fact, iLBC
    is a free codec that means less costs in deployment than in case of other but
    similar codecs. These issues make it possible to expand services and improve
    quality easily and effectively. 




    iLBC is based on block independent linear predictive coding (LPC) algorithm.
    The encoded blocks are encapsulated to be transported in a suitable protocol
    like RTP. 



    iLBC has two supported bit rates. It operates at payload bit rate of 13,33 kbps (399 bits, packetized in 50
    bytes) for the frame size of 30 ms and 15.2 kbps (303 bits, packetized in 38
    bytes) for the frame size of 20 ms. 



    It is widely used and suitable especially for real time communication like
    telephony, videoconferencing, streaming audio, messaging, archival.

    iLBC is defined in RFC 3951. It is one of the codecs
    used by Gizmo5, webRTC, Ekiga, QuteCom, Google Talk, Yahoo! Messenger, Polycom
    IP Phone and Maemo Recorder (on the Nokia N800/N810) and many others.




    Parameters and features:

    ·        
    Sampling frequency 8 kHz/16 bit (160 samples for 20 ms
    frames, 240 samples for 30 ms frames)

    ·        
    Controlled response to packet loss, delay and jitter

    ·        
    Fixed bitrate (15.2 kbit/s for 20 ms frames, 13.33
    kbit/s for 30 ms frames)

    ·        
    Fixed frame size (304 bits per block for 20 ms frames,
    400 bits per block for 30 ms frames)

    ·        
    Robustness similar to pulse code modulation (PCM) with
    packet loss concealment

    ·        
    CPU load with higher basic quality and better response
    to packet loss

    ·        
    Computational complexity in a range of G.729A

    ·        
    Royalty Free Codec

    For more info look at http://voip-sip-sdk.com/p_217-ilbc-codec-voip.html

    Regards,

    Niko

     

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