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I need to setup SIP TRUNKING between Cisco 2851 and Asterisk



I need to setup sip trunking between Cisco 2851 and Asterisk. I don't know how to start.

- First of all, Can I do it with this configuration?:

- Second, I need some data from Asterisk, Which data I need to know to setup my Cisco 2851?

Cisco Internetwork Operating System. Cisco IOS (tm) C2800NM
Cisco IOS Software: C2800NM-SPSERVICESK9-M
Software Version: 12.4(15)T9 / CME 4.1(0)

Licensing Information

Default # personal mailboxes: 12
Default # general delivery mailboxes: 5
Maximum # configurable mailboxes: 17
Maximum message space (minutes): 18000
Maximum # telephony ports: 24
Maximum # VM/AA ports: 8
Installed Packages:  Installer (Installer application)
  Thirdparty (Service Engine Thirdparty Code) 7.0.3
  Bootloader (Primary) (Service Engine Bootloader) 2.1.14
  Plug-in Enablement (Plug-in enablement pack) 7.0.3
  CUE Voicemail Language Support (Languages global pack) 7.0.3
  Global (Global manifest) 7.0.3
  Infrastructure (Service Engine Infrastructure) 7.0.3
  GPL Infrastructure (Service Engine GPL Infrastructure) 7.0.3
  Voice Mail (Voicemail application) 7.0.3
  Bootloader (Secondary) (Service Engine Bootloader)
  Core (Service Engine OS Core) 7.0.3
  Auto Attendant (Service Engine Telephony Infrastructure) 7.0.3
Installed Languages:  CUE Voicemail UK English (British English language pack) 7.0.3
5 Replies 5

Daniele Giordano

Do you have already try with this DOC?


I have 5 POTS line connected with CISCO2851XM. I established Asterisk server in Network. Could you please tell me how to configure SIP trunk and forward outgoing calls from asterisk to POTS line?

My asterisk server need username and password to register SIP trunk with Cisco Router. How could we configure it??

ex. register => username:password@Router's IP Address:5060

Kindly reply me.


Ravikumar Sadhu

I will suggest you to disable the registration (and authentication) in Asterisk and in this way, you only need to configure inbound and outbound dial peers in gateway.

By any chance if you can not disable registration in Asterisk, you will have to have commands relevant to 'voice register global' and 'voice register pool' which means you are registering Asterisk as a phone with CME. Further, you will have to configure outbound dial peer as per your requirement.

- Vivek

so you mean to say I don't use "register =>" string and just make a user and password in sip.conf for connection from cisco router. Honestly I am new in Cisco VOIP configuration. I can configure Asterisk but can't Cisco Router for VOIP. so could you help me by an example for cisco side configuration.?


Ravikumar Sadhu

I am not sure about the Asterisk configuration but if you can disable registration, then configuration in Cisco gateway will be relatively simple however you need to understand the dial peers implementation before you attempt to make any changes in your infrastructure. Suggest you to go through following document and let us know if you have any questions;

- Vivek

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