mapomme
Rated PG
|
 Posted: Thu, 04 Mar 2004 01:37:37 Post Subject: Re: D-Link DVG-1120M VoIP Gateway Review - Reply |
 |
|
| deeno wrote: | | I just want to verify if the download/upload speeds were affected because of the G711 codec used. did you try using G729 codec? G711 consumes more than 64kbps bandwidth while with g729 it is generally like 18k at most. |
I wonder if one of the factor contributing to the observed behavior is not the asymmetry of the DSL link.
This effect has been identified and studied at IETF. The results are publicized in the document BCP 69-RFC 3449 (TCP Performance Implications of Network Path Asymmetry).
It would require:
- the VoIP stream to be steady (not bursty) on the uplink
- TCP is the transport protocol used to convey data on the downlink (most likely if it is web browsing)
An interesting test would be to see what max data rate could be reached downlink with a UDP flow during a call. |
|
