Core Issue
In this instance there is a Cisco Integrated Communications System (ICS) 7750 with various two-port Foreign Exchange Office (FXO) cards. However, it was designed to replace some of the FXO solutions with a digital PRI card instead, and the question arises as to whether any additional hardware would be necessary or if the PRI card can simply replace one of the FXO cards. This is a multiservice route processor (MRP)-300-based Cisco ICS 7750 system.
Resolution
This system has two Cisco x MRP-300s with four x FXO cards, and it is desired to replace all the FXO cards with a single T1. This system has a Packet Voice digital signal processor (DSP) Module (PVDM)-256K-8 on each MRP 300. Whenever moving toward a T1, it is necessary to check the Digital Signal Processor (DSP) allocation on the machine. Most T1 implementations will require four DSPs in order to work.
For this situation, the system had a PVDM-256K-8 on both of the MRP 300 cards, so to have the required DSPs for a T1, the PVDM must be moved and installed on the primary MRP 300, or another one has to be purchased. When adding hardware, or quoting a system, it is best to check the necessary DSPs required for a particular solution.
For more information on DSP allocation for the MRP to assist in resolving these issues, refer to Understanding DSP Allocation on a Cisco ICS 7750.
