AVAYA IP office 500v2 and Ericsson MD110 COnnection via Analog extension ports

[Imran555]

Dear Friends

we have setup Avaya ip office and MD110-P via Analog extensions as described in attached Picture.
and also there is 1 more MD110-T connected to MD110-P via IP link work well

the avaya is connected to MD110-P via analog extension going to md110-P trunks
and MD110-P analog extensions connected to avaya trunks
the avaya and MD110-P work well both way calling is OK no issues
AVAYA extensions numbering start from 60000
MD110-P extension numbering start from 1000
we can call on each other extension with out access codes
there is one MD110-T connected to MD110-P via IP link from remote site.
both MD work well the remote MD110-T extensions numbering start from 1000
but with access codes like if user make call form MD110-P he dials 97-ext
and same way when user calls from MD110-T they dial 78-ext to call MD110-P users.
now from avaya we can call via MD110-P to MD110-T by using same method 97-ext
the problem is when users call from MD110-T they dial 78-ext of avaya example 6000 and phone rings too but some time there is audio for 5 seconds and disconnects the calls and some only ring when pick call get disconnect after 5 to 10 seconds.


so i need a good help from you guys to solve the issue
i hope i will get expert answer on this issue.

Best Regards