The NM-HDV2 IP Communications High-Density Digital Voice or Fax Network
Modules combines WAN Interface Card (WIC) and Voice Interface Card (VIC)
functionality to provide unparalleled flexibility and power. The NM-HDV2 is
able to support up to an optimal maximum of 256 voice channels. The actual
ceiling on voice and fax capability set by the combination of physical digital
and physical analog Telephony interfaces, codec complexity operation desired,
and transcoding or conferencing requirements.
This table lists the NM-HDV2 IP Communications High-Density Digital
Voice or Fax Network Module variants, and the product numbers to which they
IP Communications High-Density Digital Voice or Fax Network
Module, with no onboard T1/E1 controllers and one VIC/VWIC slot
One-port T1/E1 IP Communications High-Density Digital Voice or
Fax Network Module, with one onboard T1/E1 controller and one VIC/VWIC
Two-port T1/E1 IP Communications High-Density Digital Voice or
Fax Network Module, with two onboard T1/E1 controllers and one VIC/VWIC
This table lists the digital signal processor (DSP) module variants
that are used in the NM-HDV2 IP Communications High-Density Digital Voice or
Fax Network Modules, and the product numbers to which they correspond.
Maximum Number of Voice/FAX Channels per Codec
Up to two onboard T1/E1 controllers on the base NM-HDV2 module, with
software-selectable T1 or E1 personality through the Cisco IOS® Software CLI.
Both onboard controllers must be T1 or both must be E1.
Note: When the onboard controllers are configured for E1 mode, it is
possible that the E1 controllers may not come up properly even when connected
to known good E1 Telco lines. The output of the show controllers
E1 command can indicate large accumulations of Line Code
Violations (LCVs) and Path Code Violations (PCVs). The problem can be the
result of how the E1 line has been provisioned by the Telco; specifically
whether Wet Current is provided or not. On the NM-HDV2 product there are two
jumper blocks which control whether the onboard T1/E1 controllers support Wet
Current or not. These jumpers are identified on the Printed Circuit Board (PCB)
of the Network Module as J6 and J7 (see
photograph). J6 is the jumper block for onboard controller 1 while J7 is
the jumper block for onboard controller 0. The pin count for each jumper block
is from 1 to 3. Pin 1 is the rightmost pin and Pin 3 is the leftmost pin. When
Pins 1 and 2 are short-circuited (Right Jumper Setting) the onboard controller
is set for "Wet Current Mode", and when Pins 2 and 3 are short-circuited (Left
Jumper Setting) the onboard controller is set for "Normal Mode". Early
production NM-HDV2s shipped with the jumper blocks set to expect Wet Current to
be supplied by the Telco, and this causes problems for some E1 users. When you
move the setting to Normal Mode, it typically clears up the problem. Current
production NM-HDV2s now ship with the jumper blocks set for Normal Mode.
Accepts any of the VIC2-2FXS, VIC2-2FXO, VIC2-4FXO, VIC2-2E/M,
VIC2-2BRI-NT/TE, VIC-2DID, VIC-4FXS/DID, and VIC-1J1 voice cards in the
VIC/VWIC slot to permit analog, BRI, and J1 voice connectivity.
Note: On the NM-HDV2, NM-HD-1V, NM-HD-2V, and NM-HD-2VE Network Modules,
the VIC-2DID only operates in Direct-Inward-Dial (DID) mode (not Foreign
Exchange Station [FXS] mode), until Cisco IOS Software Release IOS 12.4(3) and
later. The VIC-4FXS/DID only operates in FXS mode (not DID mode) until Cisco
IOS Software Release IOS 12.3(14)T and later. Software selectable DID or FXS
mode is supported on both VICs in Cisco IOS Software Release 12.4(3) and later.
Each TI C5510 DSP can optimally support 16 G.711 voice channels in FC
mode. For other codecs in FC mode, or if the DSPs are configured for MC or HC
mode, the number of simultaneous voice channels that can be supported is shown
in Table 2.
PVDM2 DSP cards fit into single inline memory module (SIMM) sockets
on the NM-HDV2 network modules.
Four PVDM2 SIMM sockets are available on the NM-HDV2 network modules,
which allows for a maximum of 16 onboard C5510 DSPs (four PVDM2-64 cards
DSP resources may be oversubscribed, which means that digital voice
interfaces may be configured to support up to as many voice channels as the
DSPs can optimally support. Actual limits on how many simultaneous voice calls
can be supported depends on the mixture of codecs requested of the DSPs.
DSP resources may be reserved for analog and BRI voice ports to
ensure that there are DSP channels dedicated to these ports during DSP
Note: The Cisco IOS Software versions provided are typically the minimum
version required to support the platform, module, or feature in question. To
find a complete list of Cisco IOS Software versions a feature, module,
interface card, or chassis is supported in, use the
(registered customers only)