> Is 4-port ima module the smallest/cheapest module that can be used to terminate a single t1 atm service on a 2600?
You'll need to check with your sales team concerning prices, but the NM-4T1-IMA is one of the most popular module. The other option would be using the AIM-ATM in conjunction with a WIC. Check this one
http://www.cisco.com/en/US/products/sw/iosswrel/ps1839/products_feature_guide09186a0080087d41.html
> what application fits the atm-dxi l2 option?
DXI is not widely used since the introduction of other NMs supporting ATM. DXI's theory is that encapsulation can be set up for a Serial interface to communicate with an ATM DSU. However, most people opt to use the more recent options for ATM such as the NM-4T-IMA since it already contains a DSU.
http://www.cisco.com/en/US/products/sw/iosswrel/ps1826/products_configuration_guide_chapter09186a0080087f83.html
> is the advanced integration module just for enhancing performance for voatm applications or does it also increase performance for voip qos applications or other atm services, such as ima?
Since the AIM-VOICE contains the necessary DSP's, it's primary function is to enhance voice functions.
> lastly, customer is govt agency and is planning to do ip telephony hosted on a pbx, Cisco can handle ip qos on router as well as 3des gre tunnels between sites to encrypt all ip traffic, including voip between ip phones and hub pbx. my product build thus far is 2691 with ipsec/vpn accel module, 4-port ima for termination of single atm t1 with obvious scalability options, maxed with memory. If you want to scale down to 2651xm based on price. est average user count at remote offices: 10. from user/traffic perspective, seems that 2651xm may fit the bill, my concern is performance load on router based on all the applications it must support at once.
Yes, the 2651XM may be less expensive, but there's a difference of about 30Kpps between them. You should also consider the port density between both platforms.
http://www.cisco.com/en/US/products/hw/routers/ps259/products_data_sheet09186a00801761b1.html
I would suggest speaking with your Cisco sales team for a recommendation, but in my opinion, I'd look towards the 2691 for future growth and increased performance.
