[e2e] TFRC vs UDP

Filipe Abrantes fla at inescporto.pt
Thu Mar 31 07:44:43 PST 2005


Hello Syed Faisal,

TFRC, unlike UDP, may restrain the rate of the CM application, which may 
in a lower rate for that application. However, the TFRC mechanism is 
able to inform the application about the network state (bandwidth, rtt), 
which it can use to choose the more appropriate codec and switch codecs 
during a connection if network conditions change.

Estimating network conditions can also be done by the application when 
using UDP, however using a TFRC-enabled protocol (DCCP) provides an 
automated unified way of doing this to everyone.

Regards,

Filipe A.



Syed Faisal Hasan wrote:
> 
> To whom it may concern,
> 
> TFRC was designed for use by the Continuous Media (CM) applications. But 
> why will a CM application which is performing well using UDP, use TFRC 
> if there is performance gap (more latency, less number of packets 
> transmitted in the same time, high rate fluctuations in the beginning) 
> betwen UDP and TFRC ? May be thats the reason we haven't seen any 
> applicatons using TFRC. On the other hand there is no (I haven't found) 
> research which analyzes the performance difference between UDP and TFRC. 
> It is clear that TFRC will not perform exactly like UDP ( due to TFRC's 
> friendliness with TCP), but how much can we expect from TFRC?
> 
> Faisal
> 
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-- 
Filipe Lameiro Abrantes
INESC Porto
Campus da FEUP
Rua Dr. Roberto Frias, 378
4200-465 Porto
Portugal

Phone: +351 22 209 4266
E-mail: fla at inescporto.pt


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