The high density Cisco VIC-4FXO-M1 Voice Interface Card (VIC) supports up to four Foreign eXchange Office (FXO) M1 analog trunk ports. The VIC-4FXO-M1 is built from industry-proven Cisco hardware and uses industry-proven Cisco IOS Software technology. Because the Cisco VIC-4FXO-M1 is the same size as the existing two port VICs, it can slide into either one of the two VWIC slots located on the MRP card. Thus, when installing two Cisco VIC-4FXO-M1 cards within a MRP, up to eight FXO-M1 trunk ports can be supported.Within the ICS 7750 system, the Medium Complexity analog DSP image is the factory default for supporting the VIC-4FXO-M1. This DSP image provides support for four voice channels (of G.711, G.729 or G.726) for each DSP chip. For example, the PVDM-4 has one DSP chip and is therefore capable of supporting 4 voice channels on the VIC-4FXO-M1. The Medium Complexity analog DSP image supports 4 channels of G.711, G.729, G.726, fax relay, modem or fax pass through and provides support for 32 msec Echo Cancellation per DSP chip. The VIC-4FXO-M1 also supports the High Complexity analog DSP image. This DSP image provides support for two voice channels (of G.711, G.729, G.723.1 or G.726) for each DSP chip. Therefore, a PVDM-8 (two DSP chips) is required to support 4 voice channels on the VIC-4FXO-M1. The High Complexity analog DSP image supports two channels of G.711, G.729, G.726, G.723.1 fax relay, modem or fax pass through and provides support for 32msec Echo Cancellation per DSP chip.