Thank you for using the ADTRAN Support Community.
The TSU 120E does not perform dynamic T1 allocation. You must specify the channel assignments and these cannot be adjusted dynamically.
If you want to use the TSU 120E you do not need any additional modules. You are correct in your thinking - the router will connect to the V.35 and the phone system will connect to the DSX-1 port.
I hope I answered your questions,
Thank you for that prompt reply!
As a side note,
Can you recommend a CSU/DSU that uses v.35 and has the ability to perform dynamic T1 allocation?
Thank you so much for the help!
I'm afraid we don't have anything that can dynamically allocate the T1 between V.35 and DSX-1. You may wan to look into continuing to use the full T1 for IP data, and doing VoIP, and then you can set up QoS to ensure the bandwidth for the voice traffic, but for standard voice over T1 we don't have anything to dynamically adjust the bandwidth.