RE: SRST - Fallback mode and CME Redundancy

Both gateways will need to be in CME SRST mode with auto-provisioning and
HSRP to present a single IP address for the phones to register. CME routers
will not exchange active call information or configuration information and
need to be configured separately. Call preservation will not be possible and
there will be a timeout (HSRP) during which registration will not work.

If the connection from a phone to CME1 or CME2 is broken but CME1 could
still talk to CME2 there should be dial-peers pointing to each other for
necessary sets of numbers for pass-through calling. In SRST mode there is a
default loop-prevention mechanism that is enabled by default that will not
permit call from circulating back and forth in case of both routers not
being capable of setting up a call.

It's not very well documented subject and the best way would be to set it up
as simple as possible, run it and nice people on GS will probably help with
details when it's down to configurations.

Cheers,

Adel Abouchaev, CCIE# 12037, CISSP, MCSE

Netmasterclass LLC, Cisco Learning Partner

RFC821: adel_at_netmasterclass.net

E.164: +18886772669

HTTP: www.netmasterclass.net

From: ALL From_NJ [mailto:all.from.nj_at_gmail.com]
Sent: Friday, January 29, 2010 12:18 PM
To: Adel Abouchaev
Cc: Cisco certification
Subject: Re: SRST - Fallback mode and CME Redundancy

Super duper thanks!!!

;-)

Sorry for the delay in my response. This is all quite cool, and I
appreciate your effort and explanation.

On a related note, have you any experience with back up CME routers? It
seems that you can have a secondary CME router ... does this work well?
Seems like a nice solution for CME ...

Andrew

.

On Wed, Jan 27, 2010 at 5:48 PM, Adel Abouchaev <adel_at_netmasterclass.net>
wrote:

1) If you didn't configure ephones in CME SRST and you save configuration
after the phones are learned via SNAP - the config will be saved and the
next time the phones will be locally configured.

2) In CME SRST the config will include MAC address and if you type create
cnf-files under telephony-service, it will create config files.

3) Hunt groups will need to be configured on CME itself. It will not
download configuration from CUCM.

       CME SRST is not compatible with SRST, once you enter the
telephony-service command, you couldn't enter call-manager-fallback anymore.
CME SRST is configured using "srst " subset of commands under
telephony-service.

Cheers,

Adel Abouchaev, CCIE# 12037, CISSP, MCSE

Netmasterclass LLC, Cisco Learning Partner
RFC821: adel_at_netmasterclass.net
E.164: +18886772669
HTTP: www.netmasterclass.net

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

From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of ALL
From_NJ
Sent: Saturday, January 23, 2010 8:34 PM
To: Cisco certification
Subject: SRST - Fallback mode and CME Redundancy

hey team,

I do not have a setup yet, but wondered a few questions ... hope someone
knows the answers.

1) When SRST takes over it requests the configs from the phones and
configures itself. Does it actually enter these in as CLI? I assume so
...
2) Does it create the config files on the flash in case the phones reset?
3) How does SRST offering CME services know about huntgroups when the CUCM
is down? It is not clear to me how full SRST functionality understands most
of the configs ...
- I understand CME configs ... so perhaps an SRST w/ CME services is a fully
configured router? Just w/ the fallback command?

*
*change products now ...
*

4) For CME redundancy at a branch office, is this a fully configured second
router w/ just the secondary command put in? Example:

telephony-service
ip source-address <cme1> secondary <cme2>

Many TIA!!!

--
Andrew Lee Lissitz
all.from.nj_at_gmail.com
Blogs and organic groups at http://www.ccie.net