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BE6000 and SIP trunk


Now we use Cisco IP telephony based on Cisco CME. Cisco CME is installed on 2821 router with IOS C2800NM-ADVENTERPRISEK9-M, Version 12.4(24)T7. A SIP trunk is configured between CME router and telephony provider.

We plan to upgrade our telephone system and begin using Cisco CBE6000. I study the documentation and in "Cisco Business Edition Unified Communications and Collaboration Solutions for Small and Midsized Companies", I find that for SIP trunk to works in CBE6000 a Cisco Integrated Services Router with Cisco Unified Border Element is required. Or other quote from this document "Public switched telephone network (PSTN) connections using SIP is available through any Cisco Integrated Services Router voice gateway".


In this regard there is a question: what is the functions of this router when I make a trunk between CBE6000 and telephony provider SIP gateway and whether it is possible to use existing Cisco 2821 router as such router.



17 Replies 17

Yes you can use your 2821, but you will need CUBE licenses. CUBE will server as your gateway between your network and the ITSP. It will process both call signalling and media. It will server as the demarcation point between your network and the ITSP, providing security, ip address hiding etc..


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Ok. Ayodeji, thanks for you answer. As I undestand I need to use CUBE feature of the router for the folowing SIP trunk topology: CBE6000 - SIP trunk - CUBE - SIP trunk - ITSP. It is possible to configure SIP trunk directly between CBE6000 and ITSP (i.e. CBE6000 - SIP trunk - ITSP) and use Cisco 2821 router only as IP gateway between local and external network?

Yes you can, although it is not advisable. It poses a security risk and doesnt give much room for manipulation should need to make adjustments to the sip signalling. So I advise you use the gateway in between your BE and your ITSP

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Ok, once again thanks.

I hope this is last question. If I have 70 SCCP IP-phone in network and all of it can make simultaneous calls to PSTN it is correct that I need 3 pieces of FL-CUBE-25 licences for router?

Yes that will be correct

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Ayodeji, thank you very much for the help.

Hi Ayodeji,

I too have a somewhat similar query.
We have UC560 running currently at our company, the UC560 is connected to an ISDN modem from the network provider. We are now upgrading to BE6000. To connect to the ISDN E1/T1 line, we've ordered Cisco 2921 with a E1/T1 VWIC card (VWIC3-2MFT-T1/E1) which will connect to BE6000 and internal LAN. I just wanted to know what would I need to configure on 2921?
Do I need to install CUBE or just configure it to connect to ISDN line?

Many thanks for any help.





You dont need CUBE licenses or CUBE. You just need a voice gateway that will terminate your ISDN calls. Your gateway will need to have PVDMs installed on them since you will be using ISDN.

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PVDM? Was I wrong in ordering VWIC3-2MFT-T1/E1 to do the job ? Would you be able to advise please.


No, you were not wrong in ordering the VWIC card. What I am saying is that you need a PVDM along with that card. Your gateway needs to have dsps (PVDM) to convert from digital to analog encoding over the PSTN. Without this, your solution will not work

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Many thanks

Any suggestion on the part number?

We have 15 phones lines via ISDN as of now might increase to 25 in future

PVDM3-32 Will give you 32 channels. PVDM3-16 will give you 16 channels..One of those should be okay for you.

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Awesome, Thanks.

Could you please share your experience with Cisco voip for Sip line.  

Need to provide the Cisco Voip solution for 3 location 

  1. Main office – 152 Connections
  2. Site Office 1 – 128 Connections
  3.  Site Office 2 – 70 Connections.

 SIP Line from service provider terminated at Main office consisting of 20 DID/20 DOD with 400 extensions.

Can I use cisco business edition 6000S for each location or cisco business edition 6000M as centralized for 3 locations together?

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