Frame Relay Point-To-Point

Frame relay multiplexing for 4, 8, 16, 24 or 32 ports


Port Specifications
Operating Modes
Network Specifications
Network Management Port
Network Management Port Commands



The DCB Frame Relay firmware cartridge for the SR multiplexers allows your async terminals and PCs cost effective access to public frame relay networks. Point to point connections can be made at speeds up to 38,400 bps per port with composite link speeds to 128 Kbps.

Frame relay networks can offer very low cost communications links. Most international, nationwide and regional telephone companies offer frame relay. Frame relay services are priced competitively because frame relay protocols share the network bandwidth very efficiently among many users.

Public frame relay networks pass data in packets that are error corrected at the end points by the customer equipment, in this case, the DCB SR. By placing the error cor-rection burden on the customer's end point equipment, data is passed through the network very quickly. Frame relay protocol is similar to X.25 protocol without the one to two second end-to-end delay.

Frame relay networks are typically priced at a flat rate per end point, regardless of the distances between the customer locations. Frame relay service is delivered to the customer at a given access rate, such as 56 Kbps.

The DCB SR multiplexer is available in 4, 8, 16, 24 and 32 ports. The SR has a built-in RS-232-D Network Management Port for local or remote setup and management. The Network Management Port connects to any async terminal, or to a PC with a serial communications program. Each port can be configured separately for speed and flow control.

More than one SR can share a single 56/64 Kbps line using an MSU-4D line sharing unit. More than one SR can share a line faster than 64 Kbps by using a DCB frad.

For installations with multiple host SRs, the multiplexers can be rackmounted and the DCB Access Switch is recommended. The Access Switch makes local and remote management easy and convenient.

Point-To-Point Frame Relay
Asynchronous Statistical Multiplexing
4, 8, 16, 24 or 32 channels
Port Specifications
Data Format
1 Start bit
8 Data bits including parity if used
1 Stop bit
10 Bits total
Rates: 300, 1200, 1800, 2400, 4800, 9600, 19200 or 38400 bps individually selectable per port
Interface: CCITT V.24, RS-232-D
Connectors: RJ-45 (8-wire)
Buffering: 64K dynamically allocated
Port Flow Control: Set on a per port basis
Clear to Send
Busy High
Busy Low
Operating Modes
Normal on-line multiplexing
Network loopback
Network Specifications
Frame Relay composite protocol
Rates: Follows modem clock signal to 128 Kbps synchronous
Interface: CCITT V.24, RS-232-D
Connector: RS-45 (8-wire)
Error Correction: Automatic retransmission
Network to DSU cable included
Indicators (front panel)
Power, Activity, Line Error, Modem Ready, Option
Front panel push buttons for Next, ->, INCR, OK, RESET
Network Management Port
Interface: CCITT V.24, RS-232-D
Connector: RS-45 (8-wire)
Can be mapped to Port 1
Network Management Port to terminal cable included
Network Management Port Commands
Help Screen
Remote Test Message with Port Loopback
Monitor Transmit at Local Port
Monitor Receive at Local Port
Network Loopbacks
Flow Control
Active Set Time
Ping Port (echo time)

Show Configuration
Show Network Configuration
Configure Ports
Port Loopback
Device Type
Capture Port
Copy Port
Send Test Message
Activity Counters
Power requirements: 120 VAC, 30-43 Watts, .25-.36 Amps
10 1/4" x 9 3/4" x 2 1/4" (4, 8 or 16 channels)
10 1/4" x 9 3/4" x 4 1/2" (24 or 32 channels)
Internal DSU/CSU with 56, 19.2 & 9.6 Kbps.
MSU-4D for more than 1 multiplexer on a 56/64 Kbps link at host.
DCB multiport FRADS for more than 1 multiplexer on a single link greater than 64 Kbps.

Rear view of 16 channel SR Multiplexer

Data Comm for Business Inc.
2949 County Road 1000 E
Dewey, Il 61840
Voice: 217-897-6600
Toll Free: 800-4-DCB-NET
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Email: Contact Page
Fax: 217-897-8023
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