Re: [dccp] Comparison of RTP/UDP and RTP/DCCP

[Sara Landström <sara.landstrom at ltu.se>]

Hi Tom and Aylin,
actually there is a ns-2 module for DCCP supporting both TFRC and TCP-like.
See http://www.dccp.org. The code has been developed at Luleå University 
of Technology.

Regards,
Sara Landström

Phelan, Tom wrote:

> Hi Aylin,
>
> As far as using an application layer adaptation module, yes, you still need to 
> adapt at the application layer.  When DCCP reduces the allowed maximum transmit 
> rate below what you're currently sending, you'll need to shed resolution, or some 
> other technique (dropping layers is a good approach).
>
> With DCCP however, you won't need to monitor drop rate at the application layer; 
> you simply respond to the maximum transmit rate allowed by DCCP.  This could be 
> done with some explicit exchange with the DCCP layer, or an implicit method based 
> on application layer buffers, as described in draft-ietf-dccp-tfrc-media.
>
> As far as judging the performance of DCCP versus UDP, there are DCCP 
> implementations for Linux and FreeBSD (at various quality levels, but getting 
> good, I believe), and there is a TFRC module for ns.  More interesting though, is 
> how to make the judgment.  DCCP/TFRC has fair sharing of the network with TCP 
> apps as its primary motivation.  Your UDP method probably has good application 
> operation as its primary motivation.  Should the comparison be made on the basis 
> of application performance only?  Or is some two-dimensional comparison 
> necessary?
>
> Tom Phelan
>
> -----Original Message-----
> From: dccp-bounces at ietf.org [mailto:dccp-bounces at ietf.org]On Behalf Of Aylin Kantarci
> Sent: Friday, July 29, 2005 4:45 AM
> To: dccp at ietf.org
> Subject: [dccp] Comparison of RTP/UDP and RTP/DCCP
>
>
> Hello,
>
> I have implemneted a streaming software on RTP/UDP. 
> How can I compare its performance with RTP/DCCP?
> With RTP/UDP I am using an adaptation module for congestion control. 
> I am using a scalable codec and  the adaptation module drops layers in case of congestion.
> With RTP/DCCP, do I still need an adaptation module? 
> What kind of tests are required in order to successfully compare the performance  of  UDP and DCCP?
> Is simulation a better technique?  If so, is there a simulation environment with which I can perform the tests?
> Regards
>
> Yrd. Doc. Dr. Aylin Kantarcı
> http://egeweb.ege.edu.tr/~kantarci
> Bilgisayar Muhendisliği Bölümü 
> Ege Üniversitesi, IZMIR
> Tel: 0232 3434000-5316
>
>
>
>