a-law config

[Madhusudhan Rao M]

Hi,

Until now all the sites used u-law where i worked. I have a requirement where one country telco uses a-law standard. Is there any configuration that i need to put in place on the VG to support a-law or the ISDN PRI does the voice encoding

[mkchandak]

You have 2 options on how you configure codec for voip leg of the call.

1) On the voip dial-peer you configure the specific codec to be used. Here for this setup, you can configure the DP as codec g711alaw".

2) Creae a voice class codec and configure all the codecs you want to available for negotiation and configure the DP to use the same voice class codec.

Check the following link for sample of voice class codec config:

http://www.cisco.com/en/US/tech/tk1077/technologies_tech_note09186a00800b6710.shtml#cod_neg

[Madhusudhan Rao M]

Hi,

Thank You. Yes am aware of this. Am talking about the telco end. Will this config suffice or any other config required.

[mkchandak]

You dont need to do anything on Telco end. Depending on the region, the telco would choose which codec needs to be used. The VG is configured to support the codec as sent by the telco.

[kaja_2kj3]

Hi

     Telco will send the "wish list" codec, but ultimately it is upto your router will chose the codec based on the voice class class codec configured on your router.  This will be sufficient.

Please rate if this helps.

Thanks

[acampbell]

Hi,

I work in the UK - we are an ISDN PRI  E1 country - Alaw is used over the PSTN.

We need to use ulaw internally to allow old unity servers to communicate

Here is sample of a config with the CPTONE as GB (Other name for UK)

!

controller E1 0/0/0

description ISDN for PSTN ISDN CCT 222222

pri-group timeslots 1-8,16

linecode hdb3

framing CRC4

clock source line

!

!

interface Serial0/0/0:15

description ISDN for PSTN ISDN CCT 222222

no ip address

no logging event link-status

isdn switch-type primary-net5

isdn overlap-receiving

isdn overlap-receiving T302 2000

isdn incoming-voice voice

no cdp enable

!

!

voice-port 0/0:15

echo-cancel coverage 32

no vad

cptone GB

!

!

!

voice call carrier capacity active

voice rtp send-recv

voice call convert-discpi-to-prog

!voice call send-alert

!

voice class codec 1

codec preference 1 g711ulaw

codec preference 2 g711alaw

codec preference 3 g729r8

!

!

voice class h323 1

h225 timeout tcp establish 3

!

!

dial-peer voice 1 pots

description *** INCOMING CALL MATCHING ***

incoming called-number .

direct-inward-dial

port 0/0/0:15

!

!

dial-peer voice 9 pots

description *** O/G LEVEL 9 TRAFFIC TO PSTN ***

destination-pattern 9T

tone ringback alert-no-PI

progress_ind setup enable 3

progress_ind alert enable 8

progress_ind progress enable 8

progress_ind connect enable 8

direct-inward-dial

port 0/0/0:15

!

dial-peer voice 11 voip

description *** DDI RANGE 332000-332999 ***

preference 1

destination-pattern 332...

incoming called-number .

voice-class codec 1

voice-class h323 1

session target ipv4:10.10.10.12

dtmf-relay h245-alphanumeric

ip qos dscp ef media

ip qos dscp cs3 sig

no vad

!

!

dial-peer voice 12 voip

description *** DDI RANGE 332000-332999 ***

preference 2

destination-pattern 332...

incoming called-number .

voice-class codec 1

voice-class h323 1

session target ipv4:10.10.10.11

dtmf-relay h245-alphanumeric

ip qos dscp ef media

ip qos dscp cs3 sig

no vad

!

Regards,
Alex.
Please rate useful posts.

[kaja_2kj3]

Hi Alex,

     Thanks for the information.