With the release of 3cx V15 comes a new version of the Session Border Controller (SBC).
What is Session Border Controller SBC?
Session Border Controller is a unique offering from 3CX for enabling remote extensions to securely connect to a 3CX PBX with out the need top open SIP to the world. Dramatically improving security as well as bypassing a lot of NAT (Network Address Translation) issues.
For a start the capabilities. SBC now takes advantage of Mutli Treading which is a feature of most modern CPU. V14 only utilised a single CPU thread. Look at the perf
ormance gains for your self in the table below.
Supported phones the changes also allow for upto 50 handsets to be supported which is 10 times v14
Performance Gains Table
|Number of Sim Calls||10||100|
|Number of Extensions||5||50|
|Number of BLF laps||25 (5 BLFs on each phone)||250 (5 BLFs on each phone)|
Audio has been improved drastically. There were 2 elements that contributed to this improvement.
After 3CX introduced multi-threading, there developers thought. “Why not use a separate high priority thread to pass Audio?. That’s what they did, and the Audio was not being processed sequentially anymore. This improved packet flow and quality of calls. Since RTP is controlled by a separate thread, automatically they successfully reduced the number of dropped packets.
SBC extensions were still suffering from jitter as a result of audio being passed over TCP. Audio streamsa re typically passed over the internet in UDP as it has performance gains over TCP. 3cx had encountered this problem before – in the PBX Tunnel. So they solved this problem in the same way – on SBC v15 audio passes in UDP like this it inherits the speed advantages of UDP which are natural for Audio delivery and eliminate the checking features that the TCP Protocol comes with.
The below is a chart taken with 5 phones on v14 and v15.
|Number of phones = 5||SBC14||SBC15|
|Called max RFC3550 jitter (ms)||51.25||13.45|
|Called mean RFC3550 jitter (ms)||27.52||2.63|
|Called max delta (ms)||415.37||126.88|
Conclusion: Jitter reduced by 60%
on this subject can be read on the 3CX blog.