[Ccrtp-devel] RTP for distributed simulations

[Max Hofer]

I work in a project which deals with a distributed simulation. 

From the RFC 3550:
"While RTP is primarily designed to satisfy the needs of multi-participant 
multimedia conferences, it is not limited to that particular application. 
Storage of continuous data, interactive distributed simulation, active badge, 
and control and measurement applications may also find RTP applicable."

I toke a look at the ccRTP library and i think it will fit my needs for the 
project. 

My problem is, i guess, i didn't grasp the basic concept of payloads and 
profiles.

My application does not have a certain sample time. The data sent are event 
based (unpredicable).

My communcation needs are:
- dissimination using multicast
- packet counting (to implement a realiable transfer in the application layer)
- timestamp to control delivery deadlines
- application source identification

I could code those functionalities using UDP. but RTP seems to have some 
feature already implemented and so why inventing the wheel again.

The whole concept of payload and sampling doesnt work for me. How do i 
transmit a NTP timestamp with the RTP package? (i could include this 
timestamp in the data part, but then i need to do the filtering for to late 
delivered packages on the application level).

In section 5.1 there is a description for the 32 bit timestamp and how the 
sampling timestamp from the RTP package (combined with the NTP information 
from the RTCP SR packet) should be used to reconstruct the real time line.

How is this achieved using the ccRTP library?

thx
-- 
Max Hofer
APUS Software G.m.b.H.
A-8074 Raaba, Bahnhofstraße 1/1
T| +43 316 401629 11
F| +43 316 401629 9
W| www.apus.co.at
E| address@hidden