fxs to fxs internal call on the same router

[DrWily]

Hello,

I need to build a small analog phone network (12 analog phones + modem/fax) with an old 3825 router.

I already setup the router to accept call from modem/fax and routing them to the internet and it works great. The next step is to set up internal calls between phones. These calls in internal only, there are no route to outside the router.

But I don't know how to configure FXS interfaces to call between them. I have voice-port 0/0/0 to voice-port 0/0/3 and 0/2/0 to voice-port 0/2/3 and 0/3/0 to 0/3/3.

The router include 24 digitals modem and 2 PVDM2-64.

At the time the running conf for voice port is :

voice-port 0/x/x
no shutdown
ring cadence pattern11
compand-type a-law
cptone FR
station-id number x00x

Thanks for your help

[liviu.gheorghe · Accepted solution]

Hello @DrWily ,

you will have to configure some dial-peer voice in order to be able to call between FXS voice ports:

dial-peer voice 20 pots
description *** Fax ***
destination-pattern 160
port 0/0/0

dial-peer voice 30 pots
description *** Mark ***
destination-pattern 180
port 0/0/1

HTH

[vishalbhandari]

@DrWily 

To enable internal calling between your analog phones connected to the FXS ports on your Cisco 3825 router, you need to configure dial peers to route calls between the voice ports. Since your setup is purely internal, you only need POTS (Plain Old Telephone Service) dial peers to define the call routing.

Steps to configure:

1. Assign extension numbers to each FXS port.
2. Create POTS dial peers for each extension.

• Replace destination-pattern with the number you want for each phone.
• Replace port with the actual FXS port where the phone is connected.
• Do this for all your FXS ports to cover all 12 phones.

Once configured, each phone should be able to dial the other by entering the assigned extension number. Let me know if you need further tweaks!

[DrWily]

Hey, thanks for your help !

If I understand well I need for example :

voice-port 0/0/0
  no shutdown
  station-id name FXS 000
  caller-id enable
  ring cadence pattern11
  compand-type a-law
  cptone FR
  station-id number 1001

voice-port 0/0/1
no shutdown
  station-id name FXS 001
  caller-id enable
  ring cadence pattern11
  compand-type a-law
  cptone FR
  station-id number 1002

and :

dial-peer voice 1001 pots
description Phone n#1001
destination-pattern 1001
port 0/0/0

dial-peer voice 1002 pots
  description Phone n#1002
  destination-pattern 1002
  port 0/0/1

But it don't works, the recipient FXS answer by a busy tone.

You can download my original config file who works with 56k modem internet connection.

[liviu.gheorghe]

Assumption is the mother of all f...ups. 

I didn't  ask because I assumed you already had configured telephony service on the CME:

telephony-service
max-ephones 30
max-dn 150
ip source-address <IP address> port 2000
calling-number initiator
time-zone 26
time-format 24
date-format dd-mm-yy
keepalive 10
max-conferences 4 gain -6
call-forward pattern .T
web admin system name admin password cisco
dn-webedit
time-webedit
transfer-system full-consult
transfer-pattern .T
transfer-pattern ....
login timeout 10

[DrWily]

I'am sorry I forgot to mention that my knowledge in Cisco telephony is very limited. I'am a network guy not telephony guy

As a result if I understand the dial peer concept, I don't understand the telephony-service conf line that you gave me. I feel like this is for IP telephony and not analog phone but I'm probably wrong. However in the meantime I manage to get call between FXS port work without these lines.

The conf lines that works :

voice-port 0/0/0
 no shutdown
 station-id name FXS 000
 caller-id enable
 ring cadence pattern03
 compand-type a-law
 cptone FR
 station-id number 1001

voice-port 0/0/1
 no shutdown
 station-id name FXS 001
 caller-id enable
 ring cadence pattern03
 compand-type a-law
 cptone FR
 station-id number 1002

...

dial-peer voice 1001 pots
description Phone n#1001
destination-pattern 1001
port 0/0/0

dial-peer voice 1002 pots
description Phone n#1002
destination-pattern 1002
port 0/0/1

.... And so on until FXS/DID card 0/3/3

All phones ring and has a good signal. Even modem can communicate each others but speed is limited to 33k. Which led me to next question :

As as said before, this router can provide 56k v92 dialin server and it works great. Voice call with phone between FXS ports works too. But How can I get the modems to connect to each other at 56k instead of 33k max ?

I think that an outgoing modem call should be routed through MICA modems and then back (call ?) to the called modem to achieve 56k. But I'm not sure how it works or even if that's how it should be done.