[Serusers] SER / MediaProxy / B2BUA

Daniel Salama lists at infoway.net
Wed Jul 5 01:31:43 CEST 2006

Thank you for the prompt response and the explanation.

Currently, I don't have any code in place. However, I was trying to  
simplify the whole architecture. I have a SER box talking to Radius  
for authentication and accounting. I'm also using Mediaproxy as a NAT  
helper. Then, I have Asterisk for IVR auto attendant and voicemail.  
Since Mediaproxy is going to be in the media path anyhow to help in  
NAT, I just don't want to have another Asterisk server in the media  
path just for the Dial command with the timeout.

What would be an elegant alternative? I know that in the ISP dial-up  
world, Radius is more than capable of specifying max session time.  
Wouldn't SER/Mediaproxy "understand" the Radius attribute for max  
session time? I know SER doesn't stay in the media path but by being  
statefull, it can "listen" to all messages between the end points,  
including BYE. So, why couldn't SER/Mediaproxy "insert" a BYE message  
somewhere? Maybe it could be a simple as writing a simple external  
process that constantly monitors sessions time and "inserts" the BYE  
message using SER's fifo, in a similar way that serctl talks to SER.


On Jul 4, 2006, at 5:03 PM, sip wrote:

> All Asterisk B2BUA does, really (I'm referring to the script, not  
> the Asterisk
> patch itself), is authenticate a call coming in, and then lookup in  
> radius
> what the session timeout for that call should be. It then creates  
> an Asterisk
> dial string and sets the call timeout to be X number of seconds  
> based on the
> session-timer attribute in radius.
> If media proxy allows you to set session timers on the fly or has  
> some sort of
> polling system (I don't know, I've never used it), allowing you to  
> terminate a
> call after a certain period of time, then no, you wouldn't need  
> Asterisk B2BUA.
> We actually ended up only partly using Asterisk B2BUA for our  
> stuff, because
> it didn't quite do everything we wanted (it's really only a B2BUA  
> and it
> relies rather heavily on some odd conventions in radius for  
> authentication
> without a password (not really authentication)), so we coded our  
> own setup
> which keeps track of session timeouts and call costs and the like  
> and then
> uses the Asterisk B2BUA framework to create the Asterisk dial  
> string.  At this
> point, there's no real reason we couldn't replace the whole thing  
> with our own
> code (it became 95% ours in the process, but the process would have  
> gone
> NOwhere without the original code to set us in the right  
> direction). If you're
> in a similar situation with mediaproxy, and it allows session  
> timers of some
> sort, there's no real reason to NOT use your own setup.
> N.
> On Tue, 4 Jul 2006 16:51:12 -0400, Daniel Salama wrote
>> After reading this forum:
>> http://www.voipuser.org/forum_topic_4468.html
>> it made me wonder, whether or not you really need B2BUA if you
>> already have Mediaproxy in your environment. I know the purpose of
>> Mediaproxy is to help with NAT situations. However, given the fact
>> that Mediaproxy is always in the media path, couldn't it be ALSO
>> used  to "terminate" a call in progress, the same way that B2BUA
>> can? And  by B2BUA I refer to the Asterisk B2BUA, all within the
>> context of  prepaid type services.
>> Any comments?
>> Thanks,
>> Daniel
>> _______________________________________________
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>> Serusers at lists.iptel.org
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