using EEM and TCL scripts for voice

Answered Question
Mar 29th, 2010

HI all,

I'd like to use eem to check Sip dial-peer status+interface BRI status, when sip dial-peer has no answer to invite and bri interface is down the LAN interface must be shutted down. Is it possible to avhieve it using eem? I didn't find anything for eem monitoring sip dial-peers...



Correct Answer by Joe Clarke about 6 years 10 months ago

Yes, this is possible.  It will depend on the device type and version of IOS as to how it will be instrumented, though.

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Overall Rating: 5 (1 ratings)
Joe Clarke Mon, 03/29/2010 - 16:55

EEM doesn't have any ability to control the data plane currently.  Therefore, there is no direct voice tie-in.  There is a way to do Tcl scripting of some voice operations (e.g. IVR scripts), but those do not relate to EEM.

That said, if there are some show commands which provide you the data you need, you can create an EEM timer policy (i.e. one that runs periodically), parsers the show command output, and takes further action if the output contains certain patterns.  Depending on the version of IOS, this may require an EEM Tcl script, or you may be able to do it within an EEM applet.

If you need further assistance, you will need to provide your IOS version, and the exact commands (and output) which would tell you if the SIP peer isn't getting an answer and the BRI interface is truly down (I'm imagining something like "show isdn status" for this one).


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massipace Tue, 03/30/2010 - 06:47

I think there's no show command to check SIP dial-peers availability, backup peers are activated using "SIP ping options", I guess the right way to achieve the goal must consider other protocols than SIP operations for eem to work correctly, so I would like to ask: Is it possible to track reachability of a remote destination using IP SLA ping and eem togheter? maybe if I cannot check the SIP availability of the remote peer I can check the IP reachability of the remote VG or VGs, when the connectivity of the remote VGs is lost the eem script should do a "show isdn status" command, verify the keyword "active" or "inactive", if the staus is "inactive" the eem should run the command "shut" for a specific interface (BRI in my case).



Correct Answer
Joe Clarke Tue, 03/30/2010 - 09:33

Yes, this is possible.  It will depend on the device type and version of IOS as to how it will be instrumented, though.

massipace Wed, 03/31/2010 - 04:03

thank you for your suggestions, as soon as I wul have the devices I will try to configure it.



Alfred Johnson Mon, 04/04/2011 - 21:56

I was able to use EEM to detect and respond to SIP VoIP errors by polling OIDs in the Cisco MIB, and taking action when errors occur.

If there is no response from the other end of my SIP trunk to an INVITE, an OID is incremented and the EEM detects it.  When enough errors occur, I use CLI commands to cause the Cisco VGW to de-register with its proxy, do a new DNS query, which returns an SRV record with multiple proxies, so the VGW can switch to a different Proxy when one goes down.


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