That is very very neat indeed. I might even lab that up later. <br><br><div class="gmail_quote">On Sat, Dec 12, 2009 at 12:39 AM, Wes Sisk <span dir="ltr"><<a href="mailto:wsisk@cisco.com">wsisk@cisco.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div bgcolor="#ffffff" text="#000000">
yep! there are some interesting scenarios that arise where phones may
failover rather aggressively (geometric tcp). in recent cm versions
this is configurable on the phone configuration page. there are also
scenarios where router may artificially failover (dsp issues cause ios
to stop responding to crcx/dlcx/etc.)<br>
<br>
I like your idea lelio. allows you to transition all devices at a
remote site as mostly a single entity. However, it depends on choosing
the appropriate trigger event. The trigger even may differ depending
on network topology and implementation<br><font color="#888888">
<br>
/wes</font><div><div></div><div class="h5"><br>
<br>
On Friday, December 11, 2009 9:21:28 AM, Lelio Fulgenzi
<a href="mailto:lelio@uoguelph.ca" target="_blank"><lelio@uoguelph.ca></a> wrote:<br>
<blockquote type="cite">
<div style="font-family: Verdana; font-size: 10pt; color: rgb(0, 0, 0);">neat
suggestion. i just read up on eem. pretty powerful stuff. <br>
<br>
on the corollary, you could also monitor when a phone registered before
your MGCP gateways and then force the MGCP gateways to register as well
using similar ACLs.<br>
<br>
i likes it!<br>
<br>
<br>
---<br>
Lelio Fulgenzi, B.A.<br>
Senior Analyst (CCS) * University of Guelph * Guelph, Ontario N1G 2W1<br>
(519) 824-4120 x56354 (519) 767-1060 FAX (JNHN)<br>
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^<br>
"Bad grammar makes me [sic]" - Tshirt<br>
<br>
<br>
----- Original Message -----<br>
From: "Wes Sisk" <a href="mailto:wsisk@cisco.com" target="_blank"><wsisk@cisco.com></a><br>
To: "Lelio Fulgenzi" <a href="mailto:lelio@uoguelph.ca" target="_blank"><lelio@uoguelph.ca></a><br>
Cc: <a href="mailto:cisco-voip@puck.nether.net" target="_blank">cisco-voip@puck.nether.net</a>, "anand" <a href="mailto:anand.eee@gmail.com" target="_blank"><anand.eee@gmail.com></a>,
"Karen Cheng" <a href="mailto:kaz.cheng@gmail.com" target="_blank"><kaz.cheng@gmail.com></a><br>
Sent: Friday, December 11, 2009 9:13:12 AM GMT -05:00 US/Canada Eastern<br>
Subject: Re: [cisco-voip] WAN failure in call manager<br>
<br>
to be creative one could write an EEM script to monitor for gateway
losing connectivity to mgcp call agent and then implement an ACL
blocking all ip connectivity from the phone subnet toward the CM
servers. that would effectively have the router control the phone
rehome as well.<br>
<br>
/wes<br>
<br>
On Thursday, December 10, 2009 5:54:30 PM, Lelio Fulgenzi
<a href="mailto:lelio@uoguelph.ca" target="_blank"><lelio@uoguelph.ca></a>
wrote:<br>
<blockquote>
<div style="font-family: Verdana; font-size: 10pt; color: rgb(0, 0, 0);">Good
point Wes. That's what I was trying to say with respect to the last
paragraph, but reading it again, I didn't make that point clear. <br>
<br>
Yes, the gateway does maintain connectivity for it's local ports (PRI,
FXS, etc) and when it looses connectivity it triggers it's local ports
to register via SRST to itself (or another SRST router).<br>
<br>
However, regardless of that, even if a router can still talk to the
CUCM cluster, it will accept SRST registrations from phones. (see last
message sent).<br>
<br>
But I love how you manage to start with "it depends.... " ;)<br>
<br>
---<br>
Lelio Fulgenzi, B.A.<br>
Senior Analyst (CCS) * University of Guelph * Guelph, Ontario N1G 2W1<br>
(519) 824-4120 x56354 (519) 767-1060 FAX (JNHN)<br>
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^<br>
"Bad grammar makes me [sic]" - Tshirt<br>
<br>
<br>
----- Original Message -----<br>
From: "Wes Sisk" <a href="mailto:wsisk@cisco.com" target="_blank"><wsisk@cisco.com></a><br>
To: "Karen Cheng" <a href="mailto:kaz.cheng@gmail.com" target="_blank"><kaz.cheng@gmail.com></a><br>
Cc: "Lelio Fulgenzi" <a href="mailto:lelio@uoguelph.ca" target="_blank"><lelio@uoguelph.ca></a>,
<a href="mailto:cisco-voip@puck.nether.net" target="_blank">cisco-voip@puck.nether.net</a>,
"anand" <a href="mailto:anand.eee@gmail.com" target="_blank"><anand.eee@gmail.com></a><br>
Sent: Thursday, December 10, 2009 5:45:03 PM GMT -05:00 US/Canada
Eastern<br>
Subject: Re: [cisco-voip] WAN failure in call manager<br>
<br>
it depends.<br>
<br>
For MGCP functionality the gateway is monitoring CM. When failure is
detected router follows the configured fallback apllication, usually
h.323<br>
<a href="http://www.cisco.com/en/US/docs/voice_ip_comm/cusrst/admin/srst/configuration/guide/srs_wlan.html#wp1351962" target="_blank">http://www.cisco.com/en/US/docs/voice_ip_comm/cusrst/admin/srst/configuration/guide/srs_wlan.html#wp1351962</a><br>
<br>
That is only for the gateway though.<br>
<br>
Phones monitor CM connecvity. When phone loses connectivity to CM they
attempt to register with SRST router. When they register they tell the
router about their configuration.<br>
<br>
To that end it is both phone initiated and gateway initiated. The
gateway does not control all logic, nor does the phone control all
logic.<br>
<br>
/Wes<br>
<br>
On Thursday, December 10, 2009 5:32:16 PM, Karen Cheng <a href="mailto:kaz.cheng@gmail.com" target="_blank"><kaz.cheng@gmail.com></a>
wrote:<br>
<blockquote>Hi
Lelio,<br>
<br>
I don't believe that part about the phone triggering the SRST function
is true. From memory I believe the SRST router is the one that detects
the WAN failure in which after a certain amount of time (dependent on
how many servers in the CM cluster) it reconfigures itself to be the
call agent instead. It then also continues to monitor connectivity to
the CM cluster and once backup will again wait (dependent on how it is
configured, wait until no calls are active etc) before handing the call
agent functions back to the CM cluster.<br>
<br>
I may be wrong though.<br>
<br>
Karen<br>
<br>
<div class="gmail_quote">On Fri, Dec 11, 2009 at 8:21 AM, Lelio
Fulgenzi <span dir="ltr"><<a href="mailto:lelio@uoguelph.ca" target="_blank">lelio@uoguelph.ca</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>
<div style="font-family: Verdana; font-size: 10pt; color: rgb(0, 0, 0);">Correct,
during the SRST mode, the CUCM cluster is not controlling anything. The
phones register to the SRST router using a "simplified" configuration
they store in memory. The tell the router what DNs it is supposed to
have, and the router configures the appropriate dial-peers. Then using
the dynamic dial peers it can call other phones, or using the static
dial-peers (ones you program) a phone can call off-net using PSTN.<br>
<br>
Interesting thing is this, SRST is "always on" waiting for a device to
register to it. The device is what controls when it talks to the SRST
router or not. That's how you can test registering devices to the
router when the WAN really isn't down.<br>
<br>
It also means that if there is some way or scenario that your phones
may not be able to talk to CUCM, but your router can, you will have
phones that can call each other, but not out the PSTN because the
gateways are still registered to CUCM. That is, of course, if you have
MGCP gateways. If you have H323 gateways, I think it's a moot point.<br>
<br>
Of course, I could be wrong on one or two points, and would be happy to
learn something new. ;)<br>
<br>
<br>
<br>
---<br>
Lelio Fulgenzi, B.A.<br>
Senior Analyst (CCS) * University of Guelph * Guelph, Ontario N1G 2W1<br>
(519) 824-4120 x56354 (519) 767-1060 FAX (JNHN)<br>
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^<br>
"Bad grammar makes me [sic]" - Tshirt
<div>
<div><br>
<br>
<br>
----- Original Message -----<br>
From: "anand" <<a href="mailto:anand.eee@gmail.com" target="_blank">anand.eee@gmail.com</a>><br>
To: <a href="mailto:cisco-voip@puck.nether.net" target="_blank">cisco-voip@puck.nether.net</a><br>
Sent: Thursday, December 10, 2009 5:15:00 PM GMT -05:00 US/Canada
Eastern<br>
Subject: Re: [cisco-voip] WAN failure in call manager<br>
<br>
Hi,<br>
<br>
I have been breaking my head to understand the exact functions of SRST.
During the WAN failure, SRST router takes PSTN path.My question is
during this time will the call manager controls the call or Call
Manager is completely out of operation(I mean it does not take any part
in the call control on the PSTN path).<br>
<br>
</div>
</div>
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