[OpenSIPS-Users] opensips-cp CDR correlation

[Dan Pascu]

On Thursday 30 April 2009, Iñaki Baz Castillo wrote:
> Dan, I'm not trying to say which option is better. I just mean that
> doing media-relaying is not the *only* or better solution for all the
> cases.

Nobody ever claimed such a thing. I thought the point was to offer 
alternatives and let the users make up their own minds of what they want 
to use. The only reason I posted so much in this thread, was to debunk 
unsubstantiated claims about it generating more traffic or being more 
expensive.

To draw this to a conclusion, I'll just list the features for both and let 
people choose what best fits their case (if I did forgot anything feel 
free to correct it). Also let's state that this is in the context of 
accounting PSTN calls where accounting really matters. Forget about 
paranoid bosses watching their employees (even in that case one can use a 
media relay in the company LAN - as mediaproxy allows one to select a 
particular relay for a given call - to avoid traffic in and out of the 
company LAN):

Media relay based solution:

1. It doesn't generate more media traffic that other solutions when the 
relay is at the same location as the PSTN gateway. Also it doesn't require 
the extra signaling traffic that a solution based on session timers needs 
(this extra traffic will get higher for a session timer based solution as 
the requirement for better accuracy increases).
2. It is not more expensive than the B2BUA solution in terms of number of 
servers. It can even be cheaper if the relay runs on the same host as 
opensips, which is a valid possibility if the number of simultaneously 
active screams is not in the range of thousands.
3. It can do accounting with precision down to the second.
4. It requires no special settings to detect spoofed BYE requests that 
attempt to circumvent the proxy into believing that the session has ended. 
5. It can be used out of the box with the existing software.

The B2BUA based solution:

1. It generates the same amount of media traffic from the network.
2. It needs a specialized B2BUA box with custom logic.
3. The accounting precision is lower (it can have error margins of 
15-30-60 seconds). The higher the precision requirements, the more extra 
signaling traffic it will generate.
4. Needs to detect and handle spoofed BYEs.
5. Requires a custom opensips logic that integrates the B2BUA box in the 
path.

-- 
Dan