Here follows the ISDN2e specific config for a gateway connected in the Uk with DDI. An assuption is made that the DDI range is : 03333 567890 – 03333 567899 and that the internal extensions would be 3000 – 3009. In addition to this calls to the PSTN will be presented with full DDI of the calling extension.

Two very important things to be aware of when connecting ISDN2e in the Uk.

1. BT by default only present that last 6 digits on inbound DDI

2. The default companding type is u-law so you need to set it to a-law manually.

Translation-rule 1 is used to convert from the inbound DDI presentation to the internal extension number.

Translation-rule 2 is used to re-write the calling number to add a leading 9 (and the missing 0). So that a user can return the call directly from a list without editing the number.

Translation-rule 3 is used to map back from the extension to the full external DDI number.

Dial-peer 10 is used to control incoming calls (we don’t like defaults dialpeer zero).

I Have split up the outbound dial-peers so that COR (class of restriction) can be applied if we wish to.

isdn switch-type basic-net3

voice service pots
 supported-language UK

voice translation-rule 1
 rule 1 /^56789\(.\)$/ /300\1/

voice translation-rule 2
 rule 1 /^0/ /900/
 rule 2 /^1/ /901/
 rule 3 /^2/ /902/
 rule 4 /^3/ /903/
 rule 5 /^4/ /904/
 rule 6 /^5/ /905/
 rule 7 /^6/ /906/
 rule 8 /^7/ /907/
 rule 9 /^8/ /908/
 rule 10 /^9/ /909/

voice translation-rule 3
 rule 1 /300\(.\)$/ /0333356789\1/

voice translation-profile FROM_PSTN
 translate calling 2
 translate called 1

voice translation-profile TO_PSTN
 translate calling 3

interface BRI0/2/0
 description ** ISDN - DDI RANGE 03333 567890 - 9 **
 no ip address
 isdn switch-type basic-net3
 isdn point-to-point-setup
 isdn incoming-voice voice
 isdn static-tei 0

voice-port 0/2/0
 compand-type a-law
 cptone GB

dial-peer voice 10 pots
 description *** For inbound calls from PSTN ***
 translation-profile incoming FROM_PSTN
 preference 1
 incoming called-number .
 direct-inward-dial
 port 0/2/0
 forward-digits all
!
dial-peer voice 9 pots
 description *** Local Calls ***
 translation-profile outgoing TO_PSTN
 preference 1
 destination-pattern 9[1-9]T
 port 0/2/0
!
dial-peer voice 9011 pots
 description *** National Calls ***
 translation-profile outgoing TO_PSTN
 preference 1
 destination-pattern 90[1-6]T
 port 0/2/0
 prefix 0
!
dial-peer voice 907 pots
 description *** Calls to Mobiles ***
 translation-profile outgoing TO_PSTN
 preference 1
 destination-pattern 907T
 port 0/2/0
 prefix 07
!
dial-peer voice 907 pots
 description *** Calls to None Geographical Numbers ***
 translation-profile outgoing TO_PSTN
 preference 1
 destination-pattern 908T
 port 0/2/0
 prefix 08
!
dial-peer voice 909 pots
 description *** Premium Rate Calls ***
 translation-profile outgoing TO_PSTN
 preference 1
 destination-pattern 909T
 port 0/2/0
 prefix 09
!
dial-peer voice 900 pots
 description *** Internation Calls ***
 translation-profile outgoing TO_PSTN
 preference 1
 destination-pattern 900T
 port 0/2/0
 prefix 00
!

A combination of either CME or Call Manager/SRST configuration needs to be added to make more use of this configuration.