Cell Relay Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] Re: IP/SONET vs IP/ATM/SONET
> Isnt compression of voice done in VoIP ? In this case, the amount of bandwidth used > will probably be as low as in the case of AAL2 multiplexing. Right. You can of course use the same compression algorithms for VoIP. That was not meant to be my point. I only wanted to point out that there are better ways to do voice over ATM than simply using (unstructured) CES. > However, Unless IP gets a large numbers of voice packets IP is going to introduce a lot > of overhead...right ? Good point. As long as "IP guys" always point out that ATM introduces overhead (cell headers, AAL-5 trailer, LANE header) in data services and tend to claim this to be a killer argument against ATM, it is the other way round when talking of voice services. The overhead introduced for compressed voice circuits in AAL-2 compared to compressed voice in IP (with the needed IP and protocol headers; RTP on UDP? ) should be quite small when using reasonable frame sizes (long frames->large delay->service degradation). > Is there a standard as to how voice circuits are put onto IP.? A good point to start reading is the ITU-T spec H.323. This is framework document on multimedia services over packet based networks where IP is one packet based network. Johannes --------------------------------------------------------------------------- Pan Dacom GmbH Training/Consulting Johannes Krohn Robert-Bosch-Str. 32 D-63303 Dreieich Tel.: +49-6103/932-137 Fax: +49-6103/932-400 Email: krohn@ffm.pandacom.de |
|