ISDN Primary rate for voice and data remote access.

[Kevin Dorrell]

Please forgive a question from a beginner in VoIP.

Suppose I have a 2800 series router with a primary rate ISDN interface connected to the public P&T network. I use this router as a remote access server. I have my B channels in a dialer pool so that clients (routers) can dial into my router across the public ISDN network, and so into my data network.

Suppose, on the other hand, I use a 2800 series router as a gateway between my internal VoIP network and the public telephone network, and that I have a primary rate interface providing the PSTN connection. Maybe Call Manager is integrated into the 2800 ISR. That is possible isn't it?

Now my question is, is it possible to have both functions in the 2800 ISR at the same time using a single PRI connection to the PSTN? That is, with the B-channels being allocated dynamically to the Call Manager VoIP gateway service or the remote access dialup service as needed. Incoming calls would be routed according to their type: data to the remote access function, and voice calls to the gateway function. Is that feasible?

Now, lastly, is it possible to add in softmodem features on the same PRI? That is, "voice" calls go to the gateway, but if the gateway detects analog modem signals encoded on the "voice" channel then it passes the call to the soft modem, which then hooks back into the remote access dialer interfaces. Is that possible?

Or am I expecting too much of the ISR?

Thanks in advance.

Kevin Dorrell

Luxembourg

[Brandon Buffin]

Kevin,

Callmanager can be integrated with the 2800 either by running Callmanager Express on the router or by using the router as a gateway which registers with a Callmanager server. Take a look at the following posts regarding splitting up the PRI.

http://forums.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Network%20Infrastructure&topic=WAN%2C%20Routing%20and%20Switching&CommCmd=MB%3Fcmd%3Ddisplay_location%26location%3D.1dd95b27

http://forums.cisco.com/eforum/servlet/NetProf?page=netprof&forum=IP Communications and Video&topic=IP Telephony&CommCmd=MB?cmd=display_location&location=.1dd93e71

Hope this helps.

Brandon

[Kevin Dorrell]

Brandon,

Thank you for the reply. The document was interesting, and I still have to examine it in detail, but I don't think it was quite the same scenario. As I understand it, it was more about channelizing the E1 so that some channels connect to the PSTN, and others to a point-to-point WAN data service. That is not really what I need.

What I need is for the whole PRI to be connected to the P&T PSTN, and to be able to use the B-channels for voice, dialup data, or dialup modem as needed.

How to explain? I'm not sure I have the terminology, but here goes ...

Incoming calls from P&T on the ISDN:

I guess I can configure my CME/gateway to route the calls to my various IP telephones according to the called extension number - that is normal.

Can I have an extension number that connects instead into a remote access Dialer interface on the same 2800, for data? That number would be called by a remote router for an on-demand data circuit. Or perhaps have the extension number hook into the dialer pool, where the selection of the Dialer interface is made according to the PPP CHAP hostname.

Can I have another extension number that connects to a soft modem, which in turn hooks into the dialer pool or the individual Dialer interfaces?

Outgoing calls on the ISDN:

My IP telephones can place outgoing calls through the CME in the normal way.

How do my remote access Dialer interfaces place calls for their on-demand connections? Can the CME provide a dialer pool that can be used by the Dialer interfaces?

How about outgoing calls from my data network to a remote analog modem for on-demand connections? Suppose I have a remote data partner who provides a modem service. So I configure a Dialer interface with all the PPP and CHAP parameters for the connection. Can I link this to the CME to place the outgoing call, via a soft modem?

Sorry, but I am still a bit confused about how the various bit fit together.

Kevin Dorrell

Luxembourg

[Brandon Buffin]

Kevin,

Keep in mind than an ISR running CME is a router at heart that happens to be running voice capable IOS. So, you can certainly configure dialer pools/interfaces. I have a 2821 running CME which is also connected to a DSL provider that requires authentication. I configured a dialer pool and interface to accomplish this. What I'm not sure of is the possibility of using CME to provide a directory number for on-demand data connections. I believe this would be outside the realm of CME, but I'm not positive. Sorry I couldn't be more helpful. I'm sure someone else on the forum will be able to answer your question more definitively.

Brandon