Dial peer configuration !!

[vasanth.kumarpv]

while in srst mode, wan goes down and phones get registered in g/w,

my question is , how ip phone gets channels to make calls? i assume it happens throuugh pstn t1 /e1 /circuit terminated in same g/w? please answer legends:)

[Adrian Saavedra]

Hello,

Yes. It is assumed that, at least, there must be some local line(s) to PSTN connected to the SRST router.

Hope it helps, please rate if it does.

Kind regards,

- Adrian.

[gagansi]

Hi

As adrian said, you need to have PSTN to send the calls out otherwise you just keep playing internally.

/Gagan

[fdeckor]

Hi Kumar,

To answer your question, let say the call flow is as below

                                                                                    ------> IP WAN Link to VoIP network at HQ

                                                                                  /                                                                

Remote-side Gateway (with SRST configured)      

                                                                                 \

                                                                                   -------> E1 or T1 or FXO Link to PSTN network

On the Remote side Gateway, you need to configure 2 outgoing dial-peers with the same destination-pattern:

1) a VoIP dial-peer with Lower preference to route calls via HQ telephony infrastructure

    the default preference is 0 and it gives the high priority.

2) a POTS dial-peer with Higher preference to route calls via the PSTN link connected to the Voice Gateway.

    You need here to apply a translation rule to this dial-peer (or add a prefix) to match the PSTN network numbering plan.

Then when the WAN link will go down, by the vertus of the POTS dial-peer you configured on the SRST gateway, a E1/T1 channel (or FXO link) will be allocated by the voice gateway to route calls through the PSTN network.

Below is an example that illustrate how you can configure the SRST gateway to gauaranty service availabilty to call phone extensions at HQ.

Configuration example of the VoIP dial-peer to call ext 2123 at the HQ

dial-peer voice 2000 pots

destination-pattern 2…

preference 1

session target ipv4:10.1.1.1

Configuration example of the POTS dial-peer to call the same ext at HQ with its DID number (512 555 2123) via the PSTN network when the WAN link is down:

dial-peer voice 2000 pots

destination-pattern 2…

preference 2

prefix 512555

port 0/1:15

(we are assuming here that the SRST gateway is connected to the PSTN network with an E1 link)

Regards,

Frederic

Did this answer your question?

If so, please mark it Answered