Unconventional UC540 multisite deployment suggestions?

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Mar 22nd, 2010
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Hey guys,

I am putting together a proposal for a client to use UC540s in 9 different mobile environments.  Each will connect to the Internet independently and will likely employ SIP trunking for voice lines.  Each individual environment needs to be stand alone - with an independent CME, CUE, DHCP, NAT, etc.  The UC540 has (obviously) multisite capabilities, but these are designed for fixed applications where up to 5 sites will be in constant communication with one another.  In our scenario, one or more of the 9 sites may be online or offline at any given time, but it is not likely that all 9 will be active concurrently.  In the event that two of these sites are active, they may be active in the same physical location where an ethernet or phone cable can be stretched from one to another.

I am looking for an easy way to connect a combination of these vehicles together (probably only two at a time, but the two connected may vary depending on the situation) where they can employ 3 digit dialing from one extension to another from one vehicle to the other.  I am not sure that the traditional multisite deployment would really work for this customer as there are 9 potential sites (instead of the 5 supported).  Is there a way to connect two UC540s via their FXO and FXS ports and still acheive the same thing?

Thanks in advance,


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Steven DiStefano Mon, 03/22/2010 - 12:37
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Hi Seth,

Do you need voice only or data sharing and voice?

Multisite Manager in CCA configures 5 sites (both voice and data) and this is a static configuration, so there is no way to do more than 5.  The CCA tool doesnt support it because we dont support it.

However, if you want just voice, and all systems will be connected to the internet, then you can consider 2 options:

1)UC500s in each site:

Build each site independently and add some translation rules and dial peers OOB CLI for extension dialing between sites.

2) Remote workers:

Either a number of remote teleworkers (up to 10 allowed on a UC540 and up to 20 on a UC560) using  a teleworker router (again only if you want data + voice), or just the SPA525G phone (with its built in SSL Client) for voice teleworkers (single phone in each location).


sethschmautz Mon, 03/22/2010 - 12:54
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Hi Steve,

Thanks for the reply.  Due to the limitation being 5, I think the customer would accept just voice.  Each site will have 10-15 users and will have a mix of SIP and CO lines.  I therefore think that we need to stick with a UC500 at each site instead of looking at a remote teleworker configuration.

How difficult/entailed would it be to configure the OOB CLI for extension dialing between sites?  Would we need to have VPN or other direct connection between the sites or would each Internet Connection be sufficient to route the calls properly?



Steven DiStefano Mon, 03/22/2010 - 13:11
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Well, yeah, but there is going to be a 'rub'.

before we had CCA MSM do both (Voice and Data) for you, we used to support it done manual.


(This should have an update actually as it is a year old at least)

-you would do Page 1 for SIP endpoint to endpoint (UC500 to UC500)

-you would modify with Page 2 if you want to do video (point to point with H.323 between UC500 sites).

BIG Caveat:

Since the calls will not be inscide an SLA protected Service Provider network (you know, with a demarcation router and QOS markings for Signaling and Media with upstream and downstream bandwidth contract), you will need to consider some tuning you can do, but none of it will replace packet markings being honored and carried to prioritize voice traffic.    Look at page 4 to see some things you can do manually.

Big Caveat #2:

CCA will not like the fact that you modified an ACL and will not allow you to manage the Firewall once you do this.  We do have an OOB CLI Guide that can make this easier to handle, but its a conscious decision you make to abandon CCA to some degree and take on the responsibility to manage this yourself.



Use the PDS service to submit your design and let the SBSC tell you if they would support this configuration.  Then you can decide how to go forward.


sound reasonable?

sethschmautz Mon, 03/22/2010 - 16:15
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Hi Steve,

Thanks for your suggestions.  I will look at the documents that you referenced and probably check in with PDS also.  Thanks!



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