I have been going back and forth with different techs both with NEC and Cisco on the correct IOS to use for VOIP. I have Cisco's 2620 and several 2611's. They have 64 and 16, memory and flash. Cisco says that the IOS c2600-is-mz.122-11.T11.bin should work. NEC is telling me to use c2600-is-mz.122-15.T14.bin. The second IOS is too large and requires more flash and a ROM upgrade. Also NEC is saying they have doubts about my equipment.
The 2611 which has two 10 base T ethernet ports. I was told by NEC that this would cause a problem with VOIP because it is "Half Duplex" vs. Full Duplex like the fast Ethernet port.
Is this correct and have you found this port speed or processor of the 2611/2620 causes issues with VOIP?
I am hoping to not have to replace several of my 2611's and my 2620.
If anyone knows or has been in this situation and can give me some good advice I would be very appreciative.