NM-HDV Modules
One of the benefits of the NM-HDV module is toll bypass and PBX leased line
replacement, which reduces toll charges by local and long distance carriers and
eliminates monthly leased lines charges for PBX interconnections. Another is
acting as a PSTN gateway for Cisco CallManager and IP phones. As an enterprise
grows, this is a great way for VoIP to be seen as a low-cost solution to the
extraordinary expense of long distance toll charges.
The High Density Voice Network Module (NM-HDV) family supports the
Multi-flex Voice/WAN (VWIC) and VIC cards.The NM-HDV module is also
known as the Digital T1/E1 Packet Voice Trunk Network Module.The platforms
supported by the NM-HDV are VG-200, 2600, and 3600 series routers.The NMHDV
supports connections to both private branch exchanges (PBXs) and public
switched telephone networks (PSTN).A single module can scale up to 60 voice
channels.These 60 voice channels are based on medium-complexity voice compression
CODECs. Each NM-HDV module contains at least one 12-channel
Packet Voice DSP Module (PVDM-12) with a maximum of five PVDM-12s possible.
The PVDM-12 has three TI 549 DSPs, and supports 12 medium-complexity
and 6 high-complexity voice calls. Up to 6 packet voice trunk modules can be
configured in a Cisco 3660 router supporting 288 voice channels.Table 6.4 lists
all the available configuration options for the Digital T1/E1 Packet Voice Trunk
modules