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Posts tagged Voice
Connecting Voice Gateways/CME to the PSTN
Mar 4th
Today we’ll go over the process to connect an IOS voice gateway/CME (Call Manager Express) to the PSTN. I set this up last night and thought it would be a good post. I’ll briefly touch on using a SIP trunk as backup/failover too.
I’ve been running a SIP trunk to Flowroute for quite awhile, but I just recently got a “landline” from my ISP because they’re doing a promotion where it’s basically free. I’m keeping my SIP trunk, but I’ll be using it as backup since all US calling through the ISP is free. I’m using a 2811 with an NM-HD-2V and a VIC2-4FXO.
First we’ll verify that the card is recognized and working:
EDGE#sEDGE#sh voice port summ
IN OUT
PORT CH SIG-TYPE ADMIN OPER STATUS STATUS EC
=============== == ============ ===== ==== ======== ======== ==
1/1/0 -- fxo-ls up dorm idle on-hook y
1/1/1 -- fxo-ls up dorm idle on-hook y
1/1/2 -- fxo-ls up dorm idle on-hook y
1/1/3 -- fxo-ls up dorm idle on-hook y |
Everything looks good there, the router is recognizing the card and its ports. 1/1/0 is connected to the ISP’s MTA.
Now we’ll configure the dial peers:
SIP Trunk With CME
Sep 28th
In this article I’ll go over how to build a SIP Trunk to a provider with Call Manager Express, in this case we’ll use Flowroute. I will be using my 3725 with IOS “c3725-adventerprisek9-mz.124-15.T10.bin”.
First we will enable SIP, then we configure the router to register with our provider, then we’ll configure our codecs and dial peer, finally we’ll go over some show commands to verify that everything works.
Here’s how to enable SIP:
voice service voip sip |
Very simple, we just enable the SIP protocol.
Next we configure our router to register with Flowroute:
sip-ua authentication username xxxxx password 7 xxxxxxxxxx realm sip.flowroute.com calling-info pstn-to-sip from number set 1xxx7325736 no remote-party-id registrar dns:sip.flowroute.com expires 3600 |
This tells the router to register with “sip.flowroute.com” using the username and password we specified.
Next we configure our codecs:
voice class codec 1 codec preference 1 g729r8 codec preference 2 g711ulaw codec preference 3 g711alaw |
Here we specify which codecs we want to use and what order we prefer them, 1 being most preferred and 3 being least preferred. I have chosen to use g729 whenever possible as it needs much less bandwidth and sounds great.
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