With Callmanager, partitions and calling search spaces are utilized for implementing calling restrictions and creating closed dial groups. But what happens when in SRST? During SRST, any call restrictions defined within Callmanager will not apply and all devices will have unrestricted dialing. COR resolves this issue. COR (Class of Restriction) is a Cisco IOS voice gateway feature that enables calling privileges to be applied and is most commonly used with Callmanager Express and SRST.

There are two basic commands used when configuring Cisco IOS COR. The first command is dial-peer COR custom and I like to equate this to Callmanager partitions. The second command is dial-peer cor list, which I equate to Callmanager calling search spaces.

 

First, let’s start by defining all of our “partitions”:

dial-peer cor custom
name em-pt
name local-pt
name ld-pt
name intl-pt
name internal-pt

The name can be anything descriptive. I chose to use the same descriptions as those I used for partitions defined within Callmanager.

 

Next, we need to define “calling search spaces” and assign the desired partition(s):

dial-peer cor list em-css
member em-pt
!
dial-peer cor list local-css
member local-pt
!
dial-peer cor list ld-css
member ld-pt
!
dial-peer cor list intl-css
member intl-pt
!
dial-peer cor list em-local-css
member em-pt
member local-pt
member internal-pt
!
dial-peer cor list all-css
member em-pt
member local-pt
member ld-pt
member intl-pt
member internal-pt

 

Once we have defined all of our calling search spaces, we need to apply the corlists to their respective dial-peers:

dial-peer voice 1 pots
incoming called-number .
direct-inward-dial
!
dial-peer voice 911 pots
corlist outgoing em-css
destination-pattern 911
port 0/2/0:23
forward-digits 3
!
dial-peer voice 9911 pots
corlist outgoing em-css
destination-pattern 9911
port 0/2/0:23
forward-digits 3
!
dial-peer voice 7 pots
corlist outgoing local-css
destination-pattern 9[2-9]……$
port 0/2/0:23
forward-digits 7
!
dial-peer voice 11 pots
corlist outgoing ld-css
destination-pattern 91[2-9]..[2-9]……$
port 0/2/0:23
forward-digits 11
!
dial-peer voice 9011 pots
corlist outgoing intl-css
destination-pattern 9011T
port 0/2/0:23
prefix 011

 

We now need to define which devices will have which restrictions while in SRST. This is done under call-manager-fallback:

call-manager-fallback
secondary-dialtone 9
max-conferences 8 gain -6
ip source-address 10.29.201.1 port 2000
max-ephones 5
max-dn 10 dual-line
dialplan-pattern 1 6175292…. extension-length 4
voicemail 12122291600
call-forward busy 12122291600
call-forward noan 12122291600 timeout 12
cor incoming em-local-css 1 2001
cor incoming all-css 2 2002 – 2010

In the above example:
cor incoming [em-local-css] [1] [2001]
cor incoming [all-css] [2] [2002 – 2010]

cor incoming [corlist] [list #] [list of dn’s] <– applies corlist to outgoing calls from the IP phone to the router (SRST)

cor outgoing [corlist] [list #] [list of dn’s] <– applies corlist to incoming calls to IP phone from the router (SRST)

[corlist] - Name of corlist.
[list #] – Arbitrary number ranging from 1 to 20.
[list of dn’s] – Should be separated by a dash and a space when specifying a range.

******************************************************************************************************************

When implementing COR in Callmanager Express, the only difference is that instead of applying corlists to call-manager-fallback in srst, corlists are applied to ephone-dns which are technically dial-peers. To view these dial-peers created for each ephone-dn, issue a Show Telephony-Service Dial-peer.

We will need to create additional corlists with the desired partitions and apply them to their ephone-dns:

dial-peer cor list ph2-css
member em-pt
member local-pt
member internal-pt
!
dial-peer cor list ph1-css
member em-pt
member local-pt
member ld-pt
member intl-pt
member internal-pt

ephone-dn 1 dual-line
number 3001
name BR2 Ph1
call-forward busy 3600
call-forward noan 3600 timeout 18
corlist incoming ph1-css
!
!
ephone-dn 2 dual-line
number 3002
name BR2 Ph2
call-forward busy 3600
call-forward noan 3600 timeout 18
corlist incoming ph2-css

corlists are still applied to outgoing dial-peers just as with SRST.

 

A couple of things to keep in mind with COR in both CME and SRST:

** If either the incoming dial-peer or the outgoing dial-peer does not have a corlist applied, the call will succeed.

** Each dial-peer can be provisioned with an incoming AND an outgoing corlist.

 

As you can see, COR is a powerful tool and when using the Callmanager partitions and calling search spaces analogy, is very simple to understand and implement in your CME and SRST configurations.

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