Survivable Remote Site Telephony

Class of Restriction List (CORLIST)

The Cisco IOS gateway class of service configuration is accomplished using corlist configurations in the gateway. This blog is a continuation of the last CORLIST blog. The incoming corlist (keyring) configuration to meet the class of service requirements is as follows: Dial-peer cor list lobby_cos Member e911 ! Dial-peer cor list intern_cos Member e911 Member local ! Dial-peer cor list employee_cos Member e911 Member local Member longdistance ! Dial-peer cor list manager_cos Member e911 Member local Member longdistance Member international The cor list above does not provide privileges (incoming) or restrictions (outgoing) until the cor list is applied in either the incoming or outgoing direction. SRST allows a range of directory numbers (DN) to be configured with an incoming or outgoing corlist. In our example, we will not restrict calls between IP phones so I will not apply an outgoing corlist, only an incoming corlist. Any device can dial a phone number that does not have an outgoing corlist. The following corlist application will allow lobby phones in the DN range of 11000 through 11009 to dial emergency numbers, while intern, employees, and managers are given more possibilities for PSTN dialing. Call-manager-fallback Cor incoming lobby_cos 1 11000 – 11009 Cor incoming intern_cos 2 11010 – 11050 Cor incoming employee_cos 3 11051 – 11200 Cor incoming manager_cos 4 11201 - 11225 Corlists will not work with the SRST access-code command because there is no way to differentiate different dialed patterns with the access-code command. The access-code command functions in a matter similar to a legacy PBX. When the access code is dialed, the SRST router circuit switches the call to the traditional TDM interface and the stutter (delayed) dial tone heard by the calling party comes from the provider circuit. Subsequent dialed digits are analyzed and routed by the service provider. The configuration below is an example PSTN dial plan pointed to an ISDN PRI Q.931 signalling interface (port 0/0/0:23) with outgoing corlists applied to apply calling restrictions: dial-peer voice 911 pots destination-pattern 911 forward-digits all corlist outgoing e911_PSTN port 0/0/0:23 ! dial-peer voice 9911 pots destination-pattern 9911 forward-digits 3 corlist outgoing e911_PSTN port 0/0/0:23 ! dial-peer voice 910 pots destination-pattern 9[2-9]..[2-9]...... corlist outgoing local_PSTN port 0/0/0:23 ! dial-peer voice 9110 pots destination-pattern 91[2-9]..[2-9]...... prefix 1 corlist outgoing longdistance_PSTN port 0/0/0:23 ! dial-peer voice 9011 pots destination-pattern 9011T prefix 011 corlist outgoing international_PSTN port 0/0/0:23 Names in Cisco IOS are case sensitive. Be sure to match case when applying corlists. Corlists can also be applied to the following: • pots dial peers • voip dial peers • ephone-dn (Cisco Unified Communications Manager Express / CUCME)

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