We are planning on deploying the SRP521W to existing UC520 customers, and also plan on selling SRP521W units in new UC500 deployments.
I would like to have the SRP521W configured to do the following:
- Fail over to 3G backup
- Have the VPN ports forwarded to the UC520. We need VPN tunnels terminated on the UC520 to support the following:
- Cisco IP Communicator softphone
- Remote UC520 administration
- Remote CUE administration
- Multisite deployments
- Remote administration of devices behind UC520 - such as computers, network printers, network surveillance cameras, ESW switches, AP500 access points, IP phones, etc.
- Have SIP signaling passed through from the SRP521W to the UC520, and have RTP packets passed through from the SRP521W to the UC520. We do not need to worry about transcoding on the SRP521W, as the UC520, UC540, and UC560 can transcode calls if necessary. We also do not need to worry about failover to the FXO port on the SRP521W as the UC520 units we deploy normally have FXO ports. We have not yet deployed a version of the UC500 that does not have FXO ports, and probably will only sell versions that have FXO ports.
- Have the SRP521W perform network address translation
I would like to have the UC520 configured to do the following:
- Have calls go out to our IP to IP gateway. We do not want calls transcoded by the SRP521W, but we want the SIP signaling updated by the SRP521W (except for calls traversing over the site-to-site VPN tunnels, which do not require any changes to SIP signaling).
- Have inbound calls sent to the UC520 unit. We want the UC520 to do the codec negotiation that it does when it is not behind the SRP521W, and we do not want the SRP521W to transcode calls or alter the UC520 codec negotiation behavior.
- Have its NAT feature disabled. We want the SRP521W to do NAT. In SR520 in front of UC520 or SA520/SA540 in front of UC520 scenarios, NAT is normally disabled on the UC520 unit.
- Terminate the IPsec VPN tunnels