Core Issue
Currently, I/O memory is set at a level of available DRAM (10 percent). In many cases, this is a poor allocation of DRAM because in most customer environments I/O memory can be established at much lower portion of available DRAM.
T.37 is a store-and-forward method, and it needs packet memory to store fax messages. This puts a requirement of 2.0 MB of iomem and 8.0 MB of process memory to be free before admitting any T.37 fax call.
Resolution
This problem is solved by increasing the I/O memory manually. To increase the I/O memory, issue the memory-size iomem percentage command in global configuration mode.
By default, the I/O memory size is 10 percent. It can be increased to 15 percent or more depending on the application that is running. You can issue show memory summary command to verify the memory allocated.
Problem Type
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Fax and modem problems
Fax and Modem Problems
Fax store and forward problems
How to ...
How to ... voice network features
How to ... fax/modem features
Failure Type
Disk or memory issues
When Problem Occurs
Part of fax/modem handshake
FAX/Modem
T.37 store&forward offramp
T.37 store&forward onramp
Voice Gateways
IOS gateways
