Two E1 lines to HA100 using GXW4501 and two UCM6510s


Hi all,

I am little bit confused on designing a failover UCM network with 2 UCM 6510s and HA100. The problem I am facing is that the client have 2 E1 PRI lines need to terminate on the system and HA100 has only 1 E1 interface.
So I am thinking about introducing a GXW4501 to have that additional E1 support. I need your expert opinion in this matter on how to do the right connections for this scenario. Please correct me if I am wrong with the whole design. Diagram attached for your reference.


I think GXW4501 just need to connect via LAN is ok


The 4501 won’t fail over to anything but yeah, this should work. Maybe include a cold spare of the 4501.


That’s what I was thinking too


The supplier was suggesting me to use 2 x 4501 one with each of the 6510, but I didn’t understand how it will be wired in a failover scenario. Is it possible like that? otherwise I will consider keeping a cold spare incase of a 4501 failure.


But there is a problem with connecting HA100 and GXW4501 through LAN ports. If its a direct connection then how the HA100 will be established to the local LAN switch. Or is it possible to connect both through the network switch?


Direct connection is not required. When you use a 4501 you’ll need to set up a SIP trunk from the 6510 to the 4501 to access the PRI. The 6510 will connect to the 4501 over the network via a statically configured, internal, IP address.

The 4501 just converts the PRI to sip channels.


Assuming the failover occurs in the 6510, and the ha100 successfully fails over to the backup 6510, the backup unit will continue to connect to the 4501. If the 4501 fails, there is no option for a automatic failover. The second PRI will cease working. However, keeping a cold spare on hand, identically configured, and configured with the same IP address, will do in a pinch. Move the power cable the lan cable and the PRI cable from the failed 4501 to the cold spare, again assuming they are configured identically, the second unit will boot up and you’ll be back in business. The 450x units start up very quickly. They only take about 30 seconds, maybe 45 seconds.


Thank you so much for the details. I never worked with 4500s so have no idea about its deployment. Now i got an idea and will design the system accordingly.