SciDyn: Video over Frame Relay

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Video over Frame Relay:
The VFX-250S

Frame relay is typically used by a corporate enterprise or service provider to integrate LAN-to-LAN, inter-office and IBM SNA traffic over a single Frame Relay circuit. By carrying many different types of traffic over a common, managed network, the user can maximize bandwidth utilization and significantly reduce costs.

SciDyn's VFX-250S Video over Frame Relay Access Device is specifically designed to upgrade your Frame Relay or HDLC network to handle video conferencing applications. VFX-250 is the first device of its kind to transport continuous data bit-streams (such as H. 320) over Frame Relay services, allowing your video conferencing system to benefit from the cost-savings of Frame Relay technology.

Standard Features

Continuous bit-stream access
Automatic Variable Buffering
Windows software
External Clock
RXD/RTS Transmit Control
Satellite Capabilities

VFX-250S Specifications

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Network & User Interface
Connector: Female 37-pin D type to user equipment (Video codec)
Male 37-pin D type to network equipment (FRAD)
Interface: RS449 (X. 21, V. 35 and others with adapter cables)
RS422 balanced drivers and receivers and RS423 receivers

User Interface
Clock Rates: VFX-250S can accept external TT clock or it can supply clock to user equipment at the following speeds: 56, 64, 96, 128, 192, 256, 384, 512, and 768 Kbps, plus 1.024, 1.536, and 1.920 Mbps Note: The VFX-250S can accommodate a TT clock that is within +/-80 ppm of one of the standard clock speeds (listed above).
Transmission: Supports continuous full duplex data transfer at specified clock rates.

Network Interface
Clock Rates: VFX-250S requires clock from network (up to a maximum of 2.048Mbps).
Packet Parameters: Packet Length: 10 -4095 bytes DLCI: 2 byte
FCS: standard 2 bytes

Enhanced Buffer Management
A unique underlying protocol is used to negotiate a Master/ Slave relationship between two communicating VFX-250S units. This allows for an "end-to-end" management of the buffers to provide a "slip-free" data transfer. An automatic variable buffer (AVB) feature is provided in order to smooth the potential differences in delays across the range of user port clock speeds.

Serial Management Interface
Connector: Female 9 pin D type
Interface: EIA-232, 9.6 Kbps & 19.2 Kbps, 8 bits/ no parity/ 1 stop bit Configuration: Windows-based configuration software is provided with the VFX-250S which allows for the management of all the options within the unit. Alternatively, a "dumb" terminal can be used to access the menu driven configuration system directly.

Available Settings

User defined Site Name
4 configuration entries, each of which contains TX and RX DLCI settings, User Clock Speed, Packet Length, AVB mode, and RTS/ RXD control of transmitted data (TXD)
LMI type (ITU Annex A, ANSI Annex D, Frame Relay Forum, or Off)
Master, Slave, or Auto-assign settings for Enhanced Buffer Management
Local/ Remote Loopback facilities

Memory:
4 configuration entries are maintained within the memory of the VFX-250S. These can be updated from the much larger configuration library in the Windows-based configuration software. All configuration parameters are stored in non-volatile memory.

Mechanical/ Environmental
Dimensions: H: 4.6 cm (1.8") W: 21.4 cm (8.4") D: 20.9 cm (8.3")
Temperature: Operating: 0 to +50 C, Non-operating:-20 to +70 C Humidity: 10 to 90 % non-condensing
Altitude: 3,050 M (10,000 ft)

Power Supply
AC Input: 100 to 250 VAC (50 -60 Hz), 15 W Maximum
Type: Universal Desktop with IEC 320 AC input connector (can be supplied with a variety of North American/ international power cords)
Size: H: 3.8 cm (1.5") W: 6.6 cm (2.6") D: 10.2 cm (4.0")

Video over Frame Relay: The VFX-250S

Standard Features

VFX-250S Specifications

Video over Frame Relay:
The VFX-250S