ISDN Network-Specific Facilities Information Element

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Jul 8th, 2008
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We have setup of UCM6.1 > Cisco h323 gateway. We have LD PRI today off AT&T 4ess switch with the nsf-service megacom defined. Tonight AT&T is going to re-home PRI to 5ess switch.

In gateway config, there is not an option to define Megacom service for 5ess like there is for 4ess. I can define this in CCM under route pattern in the ISDN Network-Specific Facilities Information Element section.

Defining megacom service here, instead of under D channel, are their any issues? Does this pass Information Element along even when using h323 on gateway? Or do we have to switch to run MGCP in order for this to work with 5ESS?


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Kenneth Mohammed Tue, 07/08/2008 - 11:27
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I just looked in a couple of gateways that I know are using ATT megacom, and they are all using 4ess. If they are switching you to 5ess, then that particular switch may not support the megacom nsf, therefore the option not being available when you change the D channel to isdn switch-type primary-5ess.

Also, I looked in the call manager, and the megacom option seemed to be only available under the 4ess configuration on the route pattern. Im not sure if this has changed in UCM 6.1, as my customer was using CCM 4.x.

Hope that helped.

UCcomp2007 Tue, 07/08/2008 - 11:41
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Thanks for feedback Kenneth.

In 6.1 MEGACOM is option for Primary-5ESS. It also appears that the ISDN Network-Specific Facilities Information Element coming from CCM is only compatable if running MGCP. Were running h323 and do not want to change as we use Mobile Voice Access which requieres h323.

We have a ticket open with AT&T and hopefully it's not required like you point out.



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