Dear All, I presume that CCID 3 is still following RFC 3448's slow start behaviour of 1 packet per second during the start of the connection, and when the ACK is received for that packet, the INITIAL ALLOWED SENDING RATE is set to 2 packets to 4 packets per RTT appropriately. Now my question is do we still need to follow TFRC's way of starting with one packet per second to determine the RTT estimate? Since, DCCP has its initial three way handshake similar to TCP, can CCID3 use the handshake to determine the RTT and start with an initial allowed sending rate set to 3 or 4 packets accordingly? Based on this paper, using the SYN/ACK, RTT could be accurately measured. http://www.acm.org/sigs/sigcomm/ccr/archive/2002/jul02/ccr-2002-3-jiang.pdf I guess starting with one packet per second , induces an additional RTT's worth of delay which may not be good for certain applications such as VoIP running over a satellite network.. Correct me if I am wrong..thanks -- Regards, Arjuna Postdoctoral Researcher Engineering Research Lab, Department of Engineering, University of Aberdeen