In this section:


In a hosted IP communications services model, SBC is deployed both at the Service Provider and the enterprise network for security and control.

The SBC deployed in the Service Provider network secures controls and segregate Service Provider infrastructure whereas the SBC deployed in an Enterprise network controls and safeguards the SIP trunking border that connects the enterprise and service provider. Also the SBC's normalization features help Enterprises avoid hosted service interoperability issues.

Figure 1: Hosted Enterprise IP Communication Services


SBC in a Carrier-hosted IP-PBX

Figure 2: Carrier-Hosted IP-PBX


The SBC facilitates the registration of user equipment (UEs) located on the enterprise network to an IP-PBX in the carrier network. 

  • An enterprise SBC can sometimes exhibit characteristics that are similar to Access/UNI SBC and other times more like a Trunking/NNI SBC.
  • The enterprise may implement SBC capability on their network.
  • Enterprise may have multiple business locations, these may need to be treated differently from a policy perspective.
  • Users may be on a VPN from any internet access location.

Configuration Steps

  1. UEs located on the enterprise network are configured to register via an SBC to an hosted IP-PBX in the carrier network.
  2. In this configuration SBC acts in a manner similar to other access/IAD cases. However, there may be additional interoperability considerations with various vendors equipment.
  3. The IP-PBX acts like a small AS, accepting registration from endpoints and offering services/features. Carrier may virtualize a PBX and support multiple customers on the same system.