CCIE Voice Lab Preparation Notes #1

Understanding COR on Cisco IOS Gateways

• Calling privileges on IOS gateways are implemented using class of restriction (COR).
• COR lists contain CORs and are used to control call routing.
• COR lists are assigned to dial peers (Incoming COR List & Outgoing COR List).
• For each call, the incoming COR list is matched against the outgoing COR list. If the outgoing COR list is a subset of the incoming COR list, or no incoming COR list is configured, call is routed.

A COR is the building block of calling privileges. A COR list contains multiple CORs and is bound to dial peers. For CallManager Express, COR is applied to ephone-dns. For SRST, COR is applied to number range.

COR only takes in place when both incoming COR list and outgoing COR list are applied.

Normally, when configuring Outgoing COR list, we assign one COR to one Outgoing COR list, and the Outgoing COR list is analogous to the concept of Partition in CUCM, and the Incoming COR list is analogous to Calling Search Space.

Configuration Commands:

First, you need to define COR:

router(config)#dial-peer cor custom

router(config-dp-cor)#name COR-name

Then, you need to configure COR lists:

router(config)#dial-peer cor list list-name

router(config-dp-corlist)#member name

Lastly, you need to apply COR lists to incoming or outgoing dial-peers or ephone-dns.

router(config-dial-peer)#corlist incoming | outgoing list-name

router(config-ephone-dn)#corlist incoming | outgoing list-name

To apply COR lists to SRST ephones:

router(config-cm-fallback)#cor {incoming | outgoing} cor-list-name {cor-list-tag starting-number - ending-number | default}