The IP Communications High-Density Digital Voice/Fax Network Modules are an addition to the Cisco Systems^® IP Communications suite of solutions. The IP Communications High-Density Digital Voice/Fax Network Modules deliver high-density digital voice connectivity, high-density WAN connectivity, analog voice connectivity, and conferencing and transcoding capability in a network module form factor. The network modules provide enterprises, managed service providers, and service providers with the ability to directly connect the public switched telephone network (PSTN), traditional telephony equipment (such as private branch exchange (PBX), key systems, analog telephones, and fax machines), and WAN to Cisco^® 2811, 2821, 2851, 2911, 2921, 2951, 3825, 3845 and 3925, 3945 Unified Communications Routers for either IP Communications capabilities or pure toll bypass. The IP Communications High-Density Digital Voice/Fax Network Modules flexibly operates within two different Cisco Unified Communications (UC) environments-the Cisco Unified Communications Manager (UCM) system with Survivable Remote Site Telephony (SRST) or Cisco Unified Communications Manager Express (UCME). The network modules can be integrated with these IP Telephony solutions in a Unified Communications Router, to provide a complete IP Communications solution for full service branch customers.

Figure 1. NM-HDV2-2T1/E1 with a 2-Port FXS VIC

Cisco IP Communications solutions provide the means for integrating voice and data allowing users to take advantage of services such as IP telephony, integrated services, and toll-bypass. These solutions allow enterprises, managed network service providers, and service providers to reap the advantages of Unified Communications such as lower operating costs and increased productivity. Cisco Unified Communications solutions also enable packet voice technologies including voice over IP (VoIP) (including H.323, Media Gateway Control Protocol (MGCP), and Sessions Initiation Protocol (SIP), voice over Frame, voice over ATM (including AAL2 and AAL5 adaptation layers).

The IP Communications High-Density Digital Voice/Fax Network Modules are an integral part of the Cisco Unified Communications offering, delivering a versatile combination of digital voice, analog voice, and data capabilities in a single network module form factor. They not only provide the IP telephony gateway to Cisco UC architectures for calls to and from the PSTN and the WAN, but also allow enterprises to deploy networks with existing traditional telephony equipment until they are ready to migrate to IP telephony. Features include high-density digital voice and WAN connectivity up to four T1/E1 ports, analog voice connectivity up to four ports, and up to 50 conferencing and transcoding sessions1. Enterprises can now deploy all these rich features on a single network module, enabling connectivity to the PSTN, traditional telephony equipment such as PBXs, key systems, analog telephones, fax machines, and the enterprise WAN.

This product supports three network module versions, with the option of zero, one, or two built-in T1/E1 ports, as shown in Table 2. Each built-in port can be conveniently software-configured to support either T1 or E1 operation. Each network module also supports a single VIC/VWIC slot that can be fitted with a Cisco voice/WAN interface card (VWIC) or voice interface card (VIC). The Cisco VICs are daughter cards that install into the network modules and provide the interface to the PSTN and to telephony equipment (PBXs, key systems, fax machines, phones). The Cisco VWICs are daughter cards that provide the interface to the PBX, PSTN, and/or WAN. Figure 1 shows a NM-HDV2-2T1/E1 with two built-in T1/E1 ports and a VIC3-2FXS/DID in the VIC/VWIC slot.

Cisco VWICs supported include 1- and 2-port T1 and E1 interface cards with optional drop-and-insert capability along with a G.703 interface card option. These cards cover a full range of digital voice and WAN connectivity options. A variety of VIC options are supported including 2-port foreign exchange station (FXS), direct inward dial (DID), foreign exchange office (FXO), E&M (ear and mouth) analog interface cards, 4-port FXS and 4-port FXO cards and a 2-port ISDN Basic Rate Interface (BRI) digital interface card providing -40V phantom power. These cards cover the entire range of analog connectivity options along with user-side and network-side digital BRI connections. Please see Table 3 below for details on options supported.

The IP Communications High-Density Digital Voice/Fax Network Modules are used with the PVDM2 Packet Fax/Voice DSP modules, providing scalability from 4 to 120 channels and featuring the latest digital signal processing technology. A maximum of four PVDM2s can be installed on each NM-HDV2 network module. The IP Communications High-Density Digital Voice/Fax Network Modules that are deployed on the Cisco 2811, 2821, 2851, 2911, 2921, 2951, 3825, 3845, 3925 and 3945 Unified Communications Routers can also be conveniently used with the onboard PVDM2 DSP modules (on the 2800 and 3800 Series only). The PVDM2s are not supported on the Cisco 2900 and 3900 Series motherboards. Enterprises can conveniently select the minimum number and density-type PVDM2s depending on the voice channels they are deploying, and scale the number of PVDMs as they expand. These PVDM2 can be configured for high-, medium- or flex complexity via software. Flex complexity is the default configuration, and in this mode, the network module will dynamically negotiate the appropriate codec (medium or high) on a call-by-call basis depending on the PVDM2s available.

Enhanced Cisco conferencing and transcoding features on the IP Communications High-Density Digital Voice/Fax Network Modules are available. The network modules provide a hardware-based conference resource at branch offices to facilitate multiparty conferences, thereby reducing the costs of delivering conferencing resources across the WAN. Transcoding resources within the same network module further reduces bandwidth consumption and costs by compressing traffic across the WAN, and enabling communications between devices that support different codecs. Up to 50 eight-party G.711 ad-hoc conferences, and up to 32 eight-party multicodec (G.711/G.729) ad-hoc conferences can be supported on a single IP Communications High-Density Digital Voice/Fax Network Module.

The IP Communications High-Density Digital Voice/Fax Network Modules are integrated in the Cisco 2811, 2821, 2851, 2911, 2931, 2951, 3825, 3845, 3925, and 3945 Unified Communications routers and are interoperable with the full range of Cisco IP Communications solutions-including Cisco IP phones, Cisco UCM, Cisco UCME, Cisco Unity software, Cisco Unity Express, Cisco IP Contact Center (IPCC), and Cisco IPCC Express. Up to four network modules can be configured in a Cisco 3845 and 3945 Unified Communications Router, supporting up to 480 and 720 voice channels in medium complexity codec on the Cisco 3845 and 3945, respectively. The IP Communications High-Density Digital Voice/Fax Network Module combined with Survivable Remote Site Telephony (operating with Cisco UCM) or Cisco UCME in a Unified Communications Router makes an ideal single-box communications solution for IP telephony in branch offices. Table 5 lists the maximum number of network modules that are supported on a Unified Communications Router.

Important Features and Benefits

Table 1. The IP Communications Digital Voice/Fax Network Modules Provide a Wide Range of Features and Benefits

There are various applications for the IP Communications High-Density Digital Voice/Fax Network Module. In the application below, CiscoUCMat headquarters delivers the call control for IP phones at the branch offices (Figure 2). Each branch office is enhanced with SRST to maintain basic telephony services at the branch office if the WAN goes down or connectivity to the Cisco UCM is lost. The IP Communications High-Density Digital Voice/Fax Network Module is integrated into the Cisco Full Service Branch Office routers located at the branch office. There is frequent voice communication between branch offices, and the PSTN. As a result, voice calls between offices are VoIP and are routed over the WAN for telephony cost savings. The NM-HDV2-2T1/E1 is used to deliver T1 WAN access for both voice and data connectivity. Calls to external parties are placed through T1 PSTN access. In addition, the VIC/VWIC slot on the NM-HDV2-2T1/E1 is populated with a VIC3-4FXS/DID to connect to analog phones and fax machines.

Figure 2. IP Telephony Application using NM-HDV-2T1/E1 (with a VIC3-4FXS/DID), and SRST in a Full-Service Branch

Table 2. Cisco IP Communications High-Density Digital Voice/Fax Network Module

Table 3. VIC/VWIC Options for the IPC High-Density Digital Voice Network Modules

PVDM2s on a NM-HDV2 module or on the mother board of an ISR router can be shared across multiple IP Communications High-Density Digital Voice/Fax Network Modules. Please see Table 4 below for a list of PVDM2 modules supported.

PVDM3s equipped on the motherboards of the 2911, 2931, 2951, 3925, 3945 Unified Communications routers can coexist with the PVDM2s on the NM-HDV2 modules as long as they are not both installed in the same domain. The motherboard PVDM slots form one domain and each SM slot forms a separate domain. The motherboard domain can contain either all PVDM2 modules or all PVDM3 modules. An SM domain can only contain PVDM2 modules housed by the NMHDV2 carrier card. If a mix of PVDM2s and PVDM3s are detected on the motherboard slots, then the PVDM2s will be deactivated, allowing only the PVDM3s to be used actively. If PVDM2s are detected in service-module slots and PVDM3s are installed on the motherboard, then both will continue to function in their own domain and coexist.

Table 4. PVDM2 Packet Fax/Voice DSP Type and Density Supported on the IP Communications High-Density Digital Voice/Fax Network Module

The 2900 Series and 3900 Series Integrated Services Routers support Network Modules (with PVDM2s) via an adapter (part number SM-NM-ADPTR).

Table 5. Maximum Network Modules Allowed per Platform

2-Port 2nd Gen Multiflex Trunk Voice/WAN Int. Card - G.703 # VWIC2-2MFT-G703