Overview of following cisco 2800 config

Question

Here is the config of one of our routers. Can any one give an overview?

I believe its for VOIP.

We are going to replace this router with a non Cisco firewall, will there be any issue for VOIP in the internal network? If yes, may I know in what way.

application
service new-call flash:bootstrap.vxml
paramspace english index 0
paramspace english language en
paramspace english location flash
paramspace english prefix en
!
service cvp-survivability flash:survivability.tcl
paramspace english index 0
paramspace english language en
paramspace english location flash
paramspace english prefix en
!
service CVPSelfService flash:CVPSelfServiceBootstrap.vxml
!
service app_transfer flash:CVPSelfService.tcl
param CVPBackupVXMLServer <private IP address of another location>
paramspace english language en
paramspace english index 0
paramspace english location flash
param CVPSelfService-port 7000
param CVPSelfService-app HelloWorld
paramspace english prefix en
param CVPPrimaryVXMLServer <private IP address of another location>
!
service ringtone flash:ringtone.tcl
paramspace english language en
paramspace english index 0
paramspace english location flash
paramspace english prefix en
!
service cvperror flash:cvperror.tcl
paramspace english language en
paramspace english index 0
paramspace english location flash
paramspace english prefix en
!
service handoff flash:handoff.tcl
paramspace english language en
paramspace english index 0
paramspace english location flash
paramspace english prefix en

Answer 1

You are correct this is a VoIP configuration. This is part of the configuration for CVP call center survivability. If this site lost it's connection to the Internet or WAN (however its connecting back to your Data Center), the 2800 would take over call processing for the IP phones. It is used in combination with the standard SRST functionality on Cisco's ISR and ISR G2 platforms.

SRST keeps the phone operative and receiving/placing calls and CVP Survivability keeps your call center functioning.

You can read more on CVP survivability here on the Cisco Support Forums. It says, in part:

For Unified CVP calls, survivability is handled by a combination of services from a TCL script (survivability.tcl) and SRST functions.

The survivability TCL script is used to monitor the H.225 or SIP connection for all calls that ingress through the remote gateway. If a signaling failure occurs, the TCL script takes control of the call and redirects it to a configurable destination. The destination choices for the TCL script are configured as parameters in the Cisco IOS Gateway configuration.

So there should also be some .tcl files on the router which these services would use to execute their functions.

If you want more general information on Cisco's CVP product and configuring IOS device for PSTN ingress for it, I would recommend this config example/call flow guide.

---

EDIT: In the comments, you asked, what would be the impact of removing this Cisco router and replacing it with another vendor's firewall.

If you have Cisco VoIP telephones at this location, removing the Cisco ISR will remove their SRST functionality. That is to say, if you lose WAN connectivity to your CUCM cluster, the phones will have no way to stay in service.

This possible loss of service can be an acceptable risk, depending on the business purpose of this site and other factors. However, there was likely a good reason (business continuity, revenue generation, etc) for keeping those phones operational at all costs. Someone went through the effort to install the UCCE suite and CVP Survivability, which is usually VERY EXPENSIVE, not to mention complicated to build and maintain. Organizations, in my experience, don't undertake that expense and effort lightly.

Make sure that you have contacted whoever is responsible for the telephony portion of your network, and verify with them any plans for equipment replacement.