Asterisk networked with HiPath4000

Hi guys,

I am trying to implement Asterisk with Siemens Hipath4000 PBX.
Both Systems are already built and defined in diferent networks.

Asterisk network
Hipath4K network

I am trying to built a SIP trunk that will interconnect the two systems
On the Hipath4K system I have vendor SIP Trunk board (HG3550) with IP

On the Siemens Hipath4K I already have a way how to point to the Asterisk extensions thru the SIP trunk.

On the Asterisk I am planing to put another LAN interface that will be plugged into the network.
I am administering Hipath PBX for several years thought, I am not an Asterisk expert.

I am not sure if this is the right way to do it as I dont know if Asterisk wont get confused by the two LAN interfaces.
Maybe better is to use router to route the Asterisk primary LAN interface with the Hipath4K LAN segment and activate RIP protocol…

Please advise what path to take…

Any help will be highly appreciated

I guess that router would be better solution, since you are not familiar with asterisk. That way you only need to set up extensions, one trunk to hg1500 and one rule. If you need i can help with more details.
I could use some of your expertise on Hipath, if you are willing to help.