The MCS-7865I-1.5-ECS1 is specially targeted at voice messaging deployments, with more disk drive capacity to support storage of voice messages on the same server. The MCS-7865I-1.5-ECS1 is a MCS 7865I-1500 targeted at Unity deployments supporting voice messaging only. A single MCS-7865I-1.5-ECS1 can support up to 3000 voice messaging subscribers.Media Convergence Server 7865I-1500 is used with Cisco Unity for voice messaging only deployments and equipped with quad Gallatin Xeon 4 1.5GHz processors, 4GB SDRAM (2x512MB DIMM), four 36GB U320 SCSI hard disks (2xRAID 1), four 72GB U320 SCSI hard disks (RAID 10), redundant fans and redundant power supplies.