er (and eventually to the CUBE via the SIP proxy) by ICM for VRU treatment. This block of commands defines CUBE as a transcoding controller, and the DSP resources defined earlier (see Note 1 earlier in this list) will be used when transcod- ing is required for a call. 13. The IP address in this command is that of the local CUBE router itself (the IP address assigned to the GigabitEthernet0/0 interface). SMB SIP Trunk for PSTN Access For an SMB there is usually no need for a dedicated session border controller device to connect to a SIP trunk; SIP trunk traffic levels do not warrant it, nor is it cost-effective to have a separate appliance. It is usually sufficient to use a smaller device with integrated SIP routing capability, unso- phisticated session border control functions, and firewalling capability. However, SMB owners should carefully think through their SIP trunk connectivity, because the physical connection is much more likely to be shared with Internet access than the SIP trunk con- nection of a large enterprise. A shared access medium poses significantly higher security exposure than a dedicated SIP trunk and must be protected against. Figure 10-6 depicts two common SMB deployments: one with a traditional TDM keysys- tem or PBX, the other with an IP-PBX. Unlike the enterprise offerings, the SMB services are most often not pure SIP trunk offerings; they are instead managed services that most likely include the PBX (or at least the connectivity to it where the business might manage their own PBX) and offer full business communications connectivity for the company including Internet access, data connectivity to other sites (for larger businesses with mul- tiple sites), and SIP trunk access for PSTN calls. Example 10-6 provides a configuration of a Cisco IOS router configured with Cisco Unified Communications Manager Express (CME) as the managed IP-PBX, integrated Chapter 10: Deployment Scenarios 213 voice mail and auto-attendant (offered by Cisco Unity Express), SIP trunk access, fire- wall, and Internet 