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AAR with Extension mobility


Cisco documented that EM is not compatible with AAR, i am trying to work around the limitation with the following to see if it works. The scenario is as follows:

When bandwidth is not congested (without AAR)

- Singapore and shanghai configured to be in different location.

- a user (ext 901) in Singapore travel to Shanghai.

- user (ext 901) logs in to the phone in Shanghai using EM

- Once logged in at Shanghai, user 901 call a local number in Singapore by dialing 9,12345678 (where 9 is the

phone number to access the voice gateway in Singapore).

- the calls will be routed from shanghai via IP WAN to the singapore voice gateway, then out to singapore PSTN

and to the local singapore number.

When bandwidth is congested (with AAR), the desired outcome is that call should be routed via the Shanghai gateway out to Shanghai PSTN as International call.

Below is my analysis:

- Singapore user (901) travel to Shanghai and login to a shanghai phone using EM.

- The singapore user (901) call a local SG external number, 9,12345678

- CCM check the Location (tie to device) of Singapore voice gateway and phone 901. The phone will be in location say Location_Shanghai and the Singapore voice gateway will be in Location_Singapore.

CCM found that bandwidth is not sufficient for the two locations. AAR kicks in.

- Since the phone is in Shanghai, it will use the SH_AAR_CSS configured on that phone.

- Next SH_AAR_CSS needs to know what number it needs to dial using the PSTN. It needs to do two things

(a) Determine the DID of the called party – 1234-5678 in this case

(b) Determine what prefix to use to access the PSTN. This is determined by using AAR Group (tie to line/DN). Both 901 and the Singapore voice gateway are configured to be in AAR group called SG_GROUP. For calling within SG_GROUP, let’s assume we use 9,570 as the prefix

(9 is the PSTN access code), 570 is SG site code.

- Now SH_AAR_CSS knows the complete string to dial = 9,570 1234-5678

- We then have a translation pattern CH_SAME_AAR_TRANS_PT that matches 9570 and translate it to

9-001-65-12345678, where 9 is the access code to access the Shanghai voice gateway, 001 is to dial international

number, 65 is the country code in singapore.

Can anyone tell me if my concept is correct ?


Eng Wee

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Re: AAR with Extension mobility

This should work just fine, assuming that the external phone number mask configured on the called phone is configured correctly (12345678) in your casem and that your TP is such 9570XXXXXXXX translated to 900165XXXXXXXX, or you can use pre-dot strip and prefix option. This TP CSS will have an access to Shanghai Route Pattern parition.


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