Re: [dccp] SOCK_DCCP

[Ian McDonald <iam4 at cs.waikato.ac.nz>]

Arnaldo Carvalho de Melo wrote:
> Em Fri, Aug 05, 2005 at 08:35:44PM +0900, Yoshifumi Nishida escreveu:
> 
>>Hello,
>>I have one minor question.
>>Some or most? DCCP implementations use SOCK_DCCP for dccp sockets.
>>However, I found that some implementations already have another 
>>socket type which has similar concept: SOCK_CONN_DGRAM, although 
>>it has been used for ATM only and it is very rare to be seen.
>>Do we need two similar socket types?
> 
> 
> Further info about SOCK_CONN_DGRAM:
> 
> http://publib.boulder.ibm.com/infocenter/pseries/index.jsp?topic=/com.ibm.aix.doc/aixprggd/progcomc/skt_types.htm
> 
> SOCK_CONN_DGRAM:
> 
> Provides connection-oriented datagram service.  This type of socket
> supports the bidirectional flow of data, which is sequenced and
> unduplicated, but is not reliable. Because this is a connection-oriented

This is the reason we would need to be different I would suspect. DCCP
is sequenced, unduplicated and not reliable BUT it is two half
connections if data needs to flow both ways which is different to this.

Regards,

Ian