The OpenVox B400P is a half length ISDN (Integrated Services Digital Network) BRI (Basic Rate Interface) PCI (Peripheral Component Interconnect) card. The B400P provides a four ISDN BRI S/T ports, which makes it an ideal cost effective option for small to medium sized enterprise applications. OpenVox are a Fonality® Authorized / Certified Ecosystem (FACE) partner and the OpenVox B400P is officially certified for use with Trixbox®.

The B400P supports both TE (Terminal Equipment) and powered NT (Network Terminating) modes. The B400P provides functionality similar to ISDN BRI cards from alternative vendors such as the Digium® B410P, Junghanns® duoBRI and beroNet® BNXS0.

Standard PC (Personal Computer) hardware can be used along with B400P cards to provide a low cost migration path from legacy ISDN PBXs towards an Open Source IP PBX based solution. The B400P is compatible with leading open source IP PBX software such as Asterisk®, Trixbox®, and Elastix® (OpenVox are an Elastix® Strategic partner), which support all the sophisticated features of expensive high-end PBX/Voicemail platforms. Although developed primarily for Open Source IP PBX Asterisk® based applications, the B400P can be used for any Linux applications/systems that require ISDN connectivity, e.g. Linux ISDN firewalls, VoIP gateways and routers.

• On board first-in first-out (FIFO) static random-access memory (SRAM) buffers for hardware based channel switching
• Built in Dual-tone multi-frequency (DTMF) detection machine for hardware based DTMF detection
  
• Onboard multi network terminating (NT) power feeding circuit (most vendors provide this as an optional extra)
• Built in conference bridge unit which allows up to 8 conferences with an arbitrary number of members each
  
• Onboard parallel processor interface hardware watchdog for detecting Miscellaneous interrupt conditions
• Two ISDN BRI ports: 2 B channels (e.g. for two separate voice channels) and 1 D channel for signalling per port
• High quality components: The OpenVox B200P uses an ISDN controller chip from the same manufacturer (Cologne) used by Digium, Junghanns and beroNet for their ISDN cards
• Terminal Equipment (TE) mode: Receives a clock from the BRI interface to connect to a device operating in Network Termination (NT) mode, e.g. PBX line card or ISDN network provider NT1 unit
• Network Termination (NT) mode: Sources a clock to the BRI interface for connecting to a device operating in Terminal Equipment (TE) mode, e.g. PBX trunk card, router or ISDN telephone
• Point-to-multipoint mode: Standard connection mode for private ISDN users and small business users to connect multiple ISDN devices
• Point-to-point mode: Standard connection mode for business ISDN users for connecting a single ISDN device, e.g. PBX
• Full hardware and software compatibility: Compatible with most well known brands of open source computer telephony equipment

• mISDN: Supports complete BRI ETSI compliant EuroISDN DSS1 Stack for NT and TE mode
• BRIstuff: Set of patches and ISDN BRI drivers along with automated download and patching scripts for Asterisk, Zaptel and Libpri
• isdn4bsd: ISDN driver for FreeBSD 5/6/7 and NetBSD 2/3, supports EuroISDN DSS1 (point to point and point to multipoint) in NT and TE mode

• Net 3 ETSI EuroISDN (TBR3) attachment requirements for terminal equipment to connect to an ISDN using ISDN basic access
• International Telecommunication Union Telecommunication Standardization Sector (ITU-T) I.430 Basic user-network interface - Layer 1 specification
• European Telecommunications Standards Institute (ETSI) ETS 300 012-1 ISDN Basic User-Network Interface (UNI) Specification

• Line termination (100 ohms) on/off and NT/TE mode selectable using jumper settings
• Four S/T interfaces: S-bus (or S0-bus) consists of four wires (two pairs)
• RJ45 female connector: 8 wires, middle pairs (3+4, 5+6) are used for transmit/receive as per ITU-T I.430 specification
• Fully PCI 2.2 compliant: Auto-sense compatibility for both 5v and 3.3v PCI busses
• Solid tantalum capacitors: High volumetric efficiency/reliability, low Equivalent Series Resistance (ESR) and temperature stability over the range -55°C to +85°C
• Dimensions excluding PCI bracket (H x L x W): 96mm x 140mm x 15mm / 3.75” x 5.5” x 0.6"
• ROHS compliant: No lead in the Printed Circuit Board (PCB) or parts
• Certificates: CE, FCC

A spare PCI 2.2 slot is required, both 5v and 3.3v PCI buses are supported. The minimum requirements to support the card are: 800MHz processor, 128MB RAM, Linux kernel 2.4.X or 2.6.X (2.6.X recommended).

IP PBX system requirements are dependant on the open source telephony software being used and on the number of simultaneous calls to be supported. Two examples are provided in below: