GNS3 (dynamips) and Voice-Labs
I hear often that it is hard to practice/demo voice related configurations with GNS3. This is only partially true.
It is correct that GNS3 cannot substitute Multiservice routers like 28xx etc because the DSP resources cannot be emulated. For using T1/E1 or FXS/FXO connections you need the real hardware interfaces and of course another PBX/router interface to connect your T1 to. If you have a double T1 you could use a T1 x-over to let the router do both ends.
For all other configurations like Dial-peers, translation patterns, SIP-UA configurations, CME, ephone registrations, CUBE etc, GNS3 can do the job. Just an example from my own lab: I have several accounts at SIP-Providers in US and Europe to use with a standard sip-phone like X-Lite. The router can log in this SIP-account and let CME or UCM handle the call. Via this way I provide a local german PSTN-number for my german friends which makes my phones in Minnesota ring. The thing has of course a downside… they keep forgetting that I am 7h behind, but for this purpose Unity will take the call.
Where is GNS3 now coming into the ballpark? For each router you can specify only one SIP-registrar server, but I like to have all my SIP-accounts registered at the same time to route calls between them. GNS3 can now run the virtual routers, one for each SIP-provider, register your PSTN-numbers and UCM/CME can do the call handling.
by Patrick Geschwindner, Ascolta
Convert Cisco IP-Phone from SIP to Skinny (SCCP) and reverse
I have often been asked for a quick way to convert a Cisco IP-Phone between SIP and SCCP. People get their IP-Phones often from E-Bay or other 2nd hand resource for testing and practicing and they may receive them with the ”other” phone load they didn’t want. The easiest way to convert is via Autoregistration. With CME this is a litle more complex, but with UCM (v6 or higher) this is an easy task.
First of all, switch on Autoregistration. If you need help with that, there is another post by Brandon in this blog how to switch on Autoregistration.
Second, switch the Autoregistration Protocol to SIP or SCCP in the Enterprise Parameters (System -> Enterprise Parameters) . If the phone had been registered before, it needs to be deleted, otherwise it will not be considered as a “new” one and Communicationmanager will just reregister the phone.
Save the new setting and delete the phone and connect it if not yet done. The phone now will download the default configuration file and the new phone loads. It will reload multiple times, so just be a little patient.
One remark for phones being connected to the UCM behind a WAN: TFTP-downloads via a WAN can be pretty slow. A download can be between 20 and 30 minutes for all phones based on Java which are literally all but the older 7940′s and 7960′s
by Patrick Geschwindner, Ascolta
Configuring Auto-Registration in CUCM7
With CUCM you can auto-register phones provided a simple configuration is in place. While this is not rocket science it’s nice to have the walkthrough to look back on so here it goes.
Ensure that the Cisco CallManager service is enabled by going to Cisco Unified Serviceability then select Tools>Service Activation and ensure that the Call Manager Service is enabled.
Next go to Cisco Unified CM Administration and select System>Cisco Unified CM
Once there you should notice that the default configuration has auto-registration disabled.
While auto-registration is disabled the phone will cycle through showing you that registration is denied. You can see the message in the following video:
Once this has been done the phone can be reset and should pull a number from the auto range. Fun Stuff Huh? Here is the phone registering. A little shakey but taken with my Flip. :)