[cisco-voip] gatekeepers - when, why, how?

Mon Apr 12 14:59:54 EDT 2010

Thanks Justin. 

In a perfect world, I'd stick with SCCP and all would be good. They'd register to the gateway and no dial peers necessary (except for off-net). 

As I mentioned in the original message, however, it is more than likely (based on available documentation) that I will need to run MGCP to get SG3 speeds. This means running a few VG224s (up to 8) and a few (up to 8) 2901s (w/ VIC3-2FXS-E/DID=) as MGCP endpoints. 

Our fax lines are currently PSTN lines, so they operate in the event of a telephone system down. We'd like to keep that feature as they migrate to voip, which means getting them to communicate with each other as well as the PSTN. 

The reason why a stack of 2901s rather than one 3945 is because of price per port and upfront capital costs. It's cheaper to get a stack of 2901s rather than one 3945, both in the short and long term. 

These devices are all centrally located and are part of our business continuity solution, which includes emergency phones, elevator phones, etc. 

The extensions are all over the map and dial-peer wildcards wouldn't work too well. They'd be fine on the VG224s and 2901s, but I'd need something more granular on the SRST gateway to allow them to talk to each other. 

--- 
Lelio Fulgenzi, B.A. 
Senior Analyst (CCS) * University of Guelph * Guelph, Ontario N1G 2W1 
(519) 824-4120 x56354 (519) 767-1060 FAX (JNHN) 
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
Cooking with unix is easy. You just sed it and forget it. 
- LFJ (with apologies to Mr. Popeil) 

----- Original Message ----- 
From: "Justin Steinberg" <jsteinberg at gmail.com> 
To: "Lelio Fulgenzi" <lelio at uoguelph.ca> 
Cc: "Chris Ward (chrward)" <chrward at cisco.com>, "cisco-voip voyp list" <cisco-voip at puck.nether.net> 
Sent: Monday, April 12, 2010 2:09:32 PM GMT -05:00 US/Canada Eastern 
Subject: Re: [cisco-voip] gatekeepers - when, why, how? 

can you tell us about the environment and requirements for what you are trying to accomplish ? 

For a simple SRST site, it is not too difficult to use wildcard dial-peers to route calls between various IOS devices that are in SRST mode. I'm not sure how useful a gateway or SAF would be in this scenario since you would still need to configure the endpoints (FXS) with their phone numbers. 

If you have a handful of MGCP VG224s at a remote site, you would typically need h323 dial-peers on the VG224 to process calls when in SRST mode. 

Typically, I pick one IOS device to be the central SRST gateway. Usually this is the PSTN gateway. i then create a wildcard voip dial-peer for each VG224 and set a preference. the central SRST gateway will try SRST VG224 #1, if that gw has a dialpeer for the extension the call is connected, otherwise the call is rejected and send back to central SRST GW where the call is routed to the next dial-peer. it all happens fairly quickly and is transparent to the users. 

the kicker is that you need to setup 'allow connections h323 to h323' only on the central site gw and not on the vg224s - this way the vg224s properly reject calls back to the central gw for extensions that they do not own. 

the solution to all this IOS work is to configure the VG224s with SCCP and have them register back to the SRST router. depending on how many VG224s you have this may not be possible. 

On Mon, Apr 12, 2010 at 1:54 PM, Lelio Fulgenzi < lelio at uoguelph.ca > wrote: 

Thanks. Just checked the feature navigator. It mentions SAF feature is available on VG224 platform releases. 

But as I found out earlier, if SAF is not on the VG224 data sheet, it's not supported by TAC. :( 

I could always try and use a gatekeeper as a fallback. 

--- 
Lelio Fulgenzi, B.A. 
Senior Analyst (CCS) * University of Guelph * Guelph, Ontario N1G 2W1 
(519) 824-4120 x56354 (519) 767-1060 FAX (JNHN) 
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
Cooking with unix is easy. You just sed it and forget it. 
- LFJ (with apologies to Mr. Popeil) 

----- Original Message ----- 
From: "Chris Ward (chrward)" < chrward at cisco.com > 

To: "Lelio Fulgenzi" < lelio at uoguelph.ca >, "Mike King" < me at mpking.com > 
Cc: "cisco-voip voyp list" < cisco-voip at puck.nether.net > 
Sent: Monday, April 12, 2010 1:52:34 PM GMT -05:00 US/Canada Eastern 
Subject: RE: [cisco-voip] gatekeepers - when, why, how? 

SAF is modeled after EIGRP, but does not require EIGRP. If the feature navigator says you are good, maybe you are in luck. 

+Chris 

From: cisco-voip-bounces at puck.nether.net [mailto: cisco-voip-bounces at puck.nether.net ] On Behalf Of Lelio Fulgenzi 
Sent: Monday, April 12, 2010 1:44 PM 
To: Mike King 
Cc: cisco-voip voyp list 
Subject: Re: [cisco-voip] gatekeepers - when, why, how? 

Thanks Mike. Definitely clears up the configuration steps and I'll have to read up a bit more on whether a device should be a forwarder or a client, but it still doesn't mention anything about supported devices. Last I talked with the TAC, EIGRP routing was not supported on the VG224 (even stub, although it's listed in the feature navigator), so if SAF is anything like EIGRP (which it sounds like it is, I'm guessing the VG224 team might likely say no to this as well. :( 

--- 
Lelio Fulgenzi, B.A. 
Senior Analyst (CCS) * University of Guelph * Guelph, Ontario N1G 2W1 
(519) 824-4120 x56354 (519) 767-1060 FAX (JNHN) 
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
Cooking with unix is easy. You just sed it and forget it. 
- LFJ (with apologies to Mr. Popeil) 

----- Original Message ----- 
From: "Mike King" < me at mpking.com > 
To: "cisco-voip voyp list" < cisco-voip at puck.nether.net > 
Sent: Monday, April 12, 2010 12:49:28 PM GMT -05:00 US/Canada Eastern 
Subject: Re: [cisco-voip] gatekeepers - when, why, how? 

Lelio, 

Take a look at this, it might help a little: 

http://www.cisco.rw/en/US/docs/ios/saf/configuration/guide/saf_cg.pdf 

On Mon, Apr 12, 2010 at 12:11 PM, Lelio Fulgenzi < lelio at uoguelph.ca > wrote: 

hmmm, doesn't look like the VG224 supports this. :( 

--- 
Lelio Fulgenzi, B.A. 
Senior Analyst (CCS) * University of Guelph * Guelph, Ontario N1G 2W1 
(519) 824-4120 x56354 (519) 767-1060 FAX (JNHN) 
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
Cooking with unix is easy. You just sed it and forget it. 
- LFJ (with apologies to Mr. Popeil) 

----- Original Message ----- 

From: "Chris Ward (chrward)" < chrward at cisco.com > 
To: "Robert Kulagowski" < rkulagow at gmail.com > 
Cc: "Lelio Fulgenzi" < lelio at uoguelph.ca >, "cisco-voip voyp list" < cisco-voip at puck.nether.net > 
Sent: Monday, April 12, 2010 12:08:19 PM GMT -05:00 US/Canada Eastern 
Subject: RE: [cisco-voip] gatekeepers - when, why, how? 

Try this: 

http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/srnd/8x/netstruc.html 
#wp1155951 

It's from the SRND so it should be more descriptive. 

+Chris 

-----Original Message----- 
From: Robert Kulagowski [mailto: rkulagow at gmail.com ] 
Sent: Monday, April 12, 2010 11:17 AM 
To: Chris Ward (chrward) 
Cc: Lelio Fulgenzi; cisco-voip voyp list 
Subject: Re: [cisco-voip] gatekeepers - when, why, how? 

On Mon, Apr 12, 2010 at 9:09 AM, Chris Ward (chrward) 
< chrward at cisco.com > wrote: 
> Well, that just means your UCMs can't join the SAF network. The SAF 
> forwarders and other IOS devices just need a 15.X IOS and they should 
be 
> able to participate. 

Can you provide additional information on how this can be useful in a 
voice environment? Configurations, etc? The two links don't have 
much, and one basically just punts: 

" 
Q. I understand SAF can greatly simplify my voice-over-IP (VoIP) 
deployment. Where can I find more information on how to deploy SAF 
with my Unified Communications 8.0 application? 
A. Please contact the Voice Technology Group through your account 
representative or reseller for more information or visit 
http://www.cisco.com/go/saf . 
" 

Are you in the Voice Technology Group? Can we consider this a 
"contact"? :) 

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