multiple VLAN's behind a RED

Question

Hi, 
 
 Is it possible to configure a RED15 with UTM9.502 to work in this way? 
 
 Our remote sites are connected back to our data center/Call manager etc via RED15's however when using VOICE this makes DHCP very messy as currently we have all the RED's bridged. (so all sites end up in the same large subnet along with the IP phones) 
 
 I'd like to configure them so that each RED has it's own interface with it's specific subnet, this is easy enough, just add specific interfaces on the UTM for each range, however I'd also like the same RED to be able to handle a second subnet/VLAN for Voice. This is how we have all our non RED sites configured. 
 
 As soon as I re-configure a RED15's interface on the UTM to Ethernet VLAN, with an appropriate IP in the correct VLAN & the same VLAN tag as configured on the switch behind the RED. All devices connected to the RED are then unable to communicate outside of their own network. 
 
 Quick and dirty diagram below of how I would like it to work.

Any help would be much appreciated. 
 
 many thanks

JanGatzke · Answer

1. Create the bridge interface for each RED. 
 2. Create a VLAN interface with the VOIP VLAN ID and use the bridge created in step 1 as hardware device. You do not need to give the UTM an IP in the VOIP subnet. If the UTM does not route traffic for this subnet, this could break the routing. In this case just enter a dummy IP in a unused range. Because the VOIP VLAN traffic is bridged and not routed, the connected clients will get their ip configuration via DHCP. Do not forget to allow traffic from VOIP VLAN to VOIP VLAN in a firewall rule. 
 3. The red15 cannot tag / untag the traffic (you need a RED50 for that). You need a VLAN capable witch because the VOIP VLAN comes out tagged on all RED ports. 
 
 That's it.