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Trunk SIP between two UC560/540


I have a customers which have two Cisco UC560/540.
The both site are link with VPN IPSec (not with Cisco UC).
They can see together with private IP.
The Voice subnet are the same (

How can I do for link both system and than user can dial a 1xxx for site1 and 2xxx for site2 ?

Thank you for your help.

Sent from Cisco Technical Support iPhone App

2 Replies 2


Hello Stephanie,

If you use Cisco Configuration Assitant to configure Multisite dialing, voice vlan subnets are not important - they may overlap, because for multisite dialing both UCs will use their VLAN1 interfaces. So, VLAN1 subnets should be different, they cannot overlap. Also, since there is already a VPN transport configured, choose 'Dialing Only' multisite configuration in Multisite Manager (CCA -> Configure -> Telephony -> Site Management -> Multisite Manager).

The dialing scheme also should be changed - CCA will require you to choose a code for multisite dialing and assign a sight identifier (one digit) to each site, for example:

Site A:

8 - Multisite access code

1 - Site Identifier

Ext. 100-199

Site B:

8 - Multisite access code

2 - Site Identifier

Ext. 100-199

This scheme allows you to have overlapping extensions in both sites. To dial from SiteA to SiteB ext. 100, you need to dial 8-2-100. To dial from SiteB to SiteA ext. 150, you need to dial 8-1-150.

More information you may find in Cisco Configuration Assistant Guide -


Ivan Bondar

Thank you for your answer.

I configure the first site with dialing only and I export the configuration.

When I want to import on the second site I have a message who says than I must connect me on LAN for do that.

I check again but when the install was done the "LAN" are in VLAN Trunk and not use the VLAN1.

Actually I cannot connect me witch the CCA with IP of VLAN1 and the CISCO don't wan I connect me with another LAN VLAN 

Do you know also if I can show the directory for both site in SPA504G ?

Actually each site have own directory.

Thank you,


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