CUBE configuration instructions for ClearIP

This page provides details on the CUBE configuration settings for ClearIP.

High Level Description

The basic idea is to insert ClearIP into a normal configuration, as follows.

ClearIP - CUBE configuration

ClearIP - CUBE network

The CUBE should be configured to do hunting (route advance) if ClearIP returns a SIP 503 Service Unavailable. The call routing rules for this part should be:

  1. Try ClearIP first.
  2. Try other destinations, such as CUCM.

The CUBE should be configured with voice hunt serv/opt-unavail-unspecified.

The CUBE should drop the call if ClearIP returns a SIP 603 Decline. CUBE maps SIP 603 Decline events to PSTN code 21, call rejected. This is implemented by configuring the CUBE with no voice hunt call-reject.

The CUBE should optionally be configured to redirect SIP 302 Moved Temporarily messages.

These configurations are described in the following step-by-step instructions.

Instructions

Note: the examples below contain highlighted words that should be replaced with values specific to your network.

1. Set up DNS

ClearIP uses a fully-qualified domain name (FQDM) for high availability. Therefore, DNS servers must be configured to resolve the FQDN. If your CUBE doesn’t already have DNS servers configured, you must first configure DNS servers. Any DNS server that can resolve sip.clearip.com will work. The example below uses Cloudflare public DNS servers.

ip name-server 1.1.1.1 1.0.0.1
ip domain lookup

2. Configure voice hunt

These configurations make the CUBE route advance if ClearIP returns a SIP 503 Service Unavailable and drop the call if it returns a SIP 603 Decline.

voice hunt serv/opt-unavail-unspecified
no voice hunt call-reject

3. Set up Inbound Dial Peer

Dial peers are used to identify call source and destination endpoints and to define the characteristics applied to each call leg in the call connection. A dial peer is a static routing table, mapping phone numbers to interfaces or IP addresses.

The inbound dial peer configures call handling for calls entering the CUBE. Note: you may wish to change the called-number prefix depending upon your routing logic.

dial-peer voice 1000 voip
session protocol sipv2
incoming called-number 1T
codec g711ulaw

Note: Dial peer hunt with preference is used as the route advance approach. Other approaches such as dial peer group can also be used.

4. Set up outbound dial peer for ClearIP

The outbound dial peer for ClearIP routes calls from the CUBE to ClearIP.

dial-peer voice 2000 voip
preference 1
destination-pattern 1T
session protocol sipv2
session target dns:sip.clearip.com
session transport tcp
codec g711ulaw

Note: DNS must be configured to access ClearIP. Do not configure ClearIP with IP addresses. Only TCP and TLS are supported.

5. Configure the outbound dial peer for CUCM

The outbound dial peer for CUCM routes calls from ClearIP to the CUCM. Set up the IP address to the CUCM.

dial-peer voice 2001 voip
preference 2
destination-pattern 1T
session protocol sipv2
session target ipv4:<CUCMIP>
codec g711ulaw

6. Set up a Dial Peer Group (optional)

If your network has many dial peers and typical routing scenarios generally will evaluate subsets of dial peers, then you can make your network more efficient by creating dial peer groups for more precise, clear routing selection.

voice class dpg 100
dial-peer 2000 preference 1
dial-peer 3000 preference 2

Note: ClearIP dial peer should have the highest preference among the dial peers in the dial peer group.

7. Configure redirect (optional)

This configuration makes the CUBE to use SIP 302 Moved Temporarily responses to redirect the call.

voice service voip
no notify redirect ip2ip
sip-ua
redirection