Hello gents,
I have a customer which I need to provide a Trunk SIP to Service Provider. The connection to PBX (Alcatel OXE R10) will be done using E1 interfaces (alcatel is not IP Enable).
I have a Cisco 3945 ISRG2 that make conversion between E1 (ISDN) interfaces and SP SIP network.
Fax is an important subject for the customer and I have some questions on this item:
- for T.38 fax support, I need to have DSP configured (T.38 is medium complexity codec).
- T.38 work in fax-relay mode, correct?
- They have SG3 fax. To enable fax calls at SG3 speed, I need to support T38 v3.0 (on all endpoints / GW) and enable fax pass-through. Correct?
Issue is that I don't support fax pass-through on SP Voice network.
So final question is: do I support SG3 fax calls (maybe by lowering speed to G3) if I configure T38 fax-relay on my GW? Is there any consideration I need to take into account (DSP, Codec...)?
For example, on my GW, I will have 240 simultaneous voice calls and 80 fax calls.
for DSP calculation, I have take 320 low complexity calls and added 80 transcoding sessions to medium complexity.
Is it correct or do I need to select 240 low complexity calls and 80 medium complexity calls and no transcoding (DSP for transcoding included in medium complexity calls)?
Thanks for your help.