hi Amish < snip > With Diastar we use SIGTRAN over SCTP towards the PSTN. Do we not loose all the SCTP benefits by now using TCP from Diastar to Asterisk? As an example, SCTP reduces head-of-line blocking while using TCP from Diastar to Asterisk reintroduces head-on-line blocking. Best Regards, Amish < snip> Yes you loose out on performance using TCP rather than SCTP, but it should work ok on small-scale implementations where performance is not critical. However - SCTP was designed to solve some of the issues with signalling over TCP. Jan On 02/08/2010 09:55 PM, John Hermanski wrote: Hi Amish, The main advantage of the client/server relation ship between the DiaStar server and the Asterisk client is to be able to provide a distributed system where it is possible to separate the signaling and network connections (DiaStar) from the application services. (Asterisk) This is an advantage for larger systems. Multiple standard, easily built Asterisk boxes can added or removed on the fly without any adjustments to DiaStar. There?s a clean separation between the application and network connectivity. While, as you point out, it may be possible to be more efficient by moving M3UA to the Asterisk systems, our base SS7 products (Dialogic Distributed Signaling Interface or DSI) do not allow this. The various SS7 components that make up SIGTRAN/ISUP operate as separate processes communicating by means of Unix message queues. They are controlled by a master process that reads the SS7 configuration and then starts up the needed stacks on the single system. DiaStar uses DSI, so we have to live within its constraints. So, rather than dividing work load based on routing contexts or keys, call distribution to multiple Asterisk systems is done by means of a ?who?s least busy and replies first? to the server?s request for someone to handle an inbound call. A ?Hello? message is sent from DiaStar, via Woomera, (the protocol used between Asterisk and DiaStar) to all Asterisk systems that have registered with the server. The Asterisk system who replies first (presumably the least busy system) will be granted the call. We think this is a reasonable way of call distribution. John Hermanski Technical Marketing Engineer Dialogic Inc. 5 Monroe St. Salem, MA USA Tel: 978 744 9098 Cell: 978 836 8028 Email: john.hermanski at dialogic.com Web: www.dialogic.com This e-mail is intended only for the named recipient(s) and may contain information that is privileged, confidential and/or exempt from disclosure under applicable law. No waiver of privilege, confidence or otherwise is intended by virtue of communication via the internet. Any unauthorized use, dissemination or copying is strictly prohibited. If you have received this e-mail in error, or are not named as a recipient, please immediately notify the sender and destroy all copies of this e-mail. _________________________________________________________________ Hotmail: Free, trusted and rich email service. https://signup.live.com/signup.aspx?id=60969 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.digium.com/pipermail/asterisk-ss7/attachments/20100209/a490b0ab/attachment.htm
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