GCN-XML and Dakota

[rdenny at dc3.com]

Perhaps I missed part of this thread... But the reason for Transport listeners (as opposed to senders, brokers) to initiate the TCP connection is simple. It avoids the broker operator needing to maintain a list of subscribers. Instead, anyone can subscribe (unless otherwise restricted by IP whitelisting or digisig restriction). My broker is set up for "Come one come all... Get'cha VOEvents here!" I don't need to know who is subscribing, and I don't care. By design, and a good job by Allan and White!!!

  -- Bob


On Jan 26, 2012, at 9:10, Alasdair Allan <aa at astro.ex.ac.uk> wrote:

> 
>>> -- Each uses the uncommon idea that the receiver of the message initiates the connection (usually the sender connects).
>> 
>> Regardless of whether we regard that as "uncommon" or not, I'm not actually sure that it's correct.
>> 
>> What you describe is certainly true or the vTCP protocol. However, my understanding is that the GCN system is the reverse. To quote (from the comments in xml_sock_demo.c):
> 
> This was certainly true of the 40-byte packet system. I haven't looked at the XML system...
> 
> Al.
>