SBC vs Soft Switch in NGN
SBC (Session Border Controller)
SBC is a Voice over IP device, generally placed in the boundary of the networks to act as back to back user agent. Even though it is a single box logically it handles two main functionality which is signalling and media. It’s an intelligent device which does manipulation in signalling, media and DTMF tones. According to some definitions it’s a security device to Next Generation Network act as a border gateway. As a security device it offers, NAT facility, some firewall functionality, topology hiding and typical network attacks prevention.
At the moment SBC supports for SIP and H323 signalling protocol. SBC can do translation between SIP and H323 and vice versa. Same as in Signalling, SBC can do media transcoding as well as DTMF (Dual-Tone Multi Frequency) translation.
Soft Switch
Soft Switch is a hardware device fully controlled by software that supports call handing functionality typically like in traditional telephone switch without call switching matrix. But the main good thing is, it can handle both voice over IP calls and traditional PSTN and ISDN kind of calls thus it understand SIP,H323,C7 or SS7,H.248 and SIGTRAN. In NGN media part is handled by Media Gateways. It’s a centralised brain of the whole network which mainly does call control function with routing decisions, least cost routings and quality based routings.
Media part is handled by Media Gateways or SBC thus transcoding or DTMF translation will be done in SBC or Media Gateways.
| Difference Between SBC and Soft Switch |
(1) SBC is basically a back to back user agent which understands SIP and H323 where as Soft Switch handles both traditional C7 and VoIP calls by understanding SS7,SIGTRAN,H248,SIP,H323,SIP-I and SIP-T.(2) Soft Switch can handle large volume of calls whereas SBC will not handle large volume. (3) Soft Switch is more expensive to deploy whereas SBC is cheaper and easy to deploy. (4) Both SBC and Soft Switch vendors have GUI interface for configuration and management. (5) Transcoding and DTMF translation is handled by SBS not in Soft Switch. (6) Soft Switch is mostly connected with internal network whereas SBCs are generally border elements connecting two different networks via private or public connections. (7) SIP header manipulation and A Number, B Number manipulation are extremely handled in SBC whereas in Soft Switch it’s lesser. (8) SBC is basically a border security gateway designed in a way to protect security threats in IP connection whereas Soft Switch is a main switching element generally connected in internal network via QoS enabled MPSL network. |