The DCB PPP-SR01-DSU PPP-SR-DSU a DSU, Ethernet  router for one to four PC's connecting to a corporate network or Internet service provider.

The DCB PPP-SR-DSU replaces a DSU, router and Ethernet network interface card (NIC) at remote locations for one to four PC's connecting to a corporate network or Internet service provider. The PPP-SR-DSU allows computers using async dial PPP programs (Windows95 Dial Up Networking, Chameleon, Spry etc.) to connect on a permanent private line link.

The DCB PPP-SR-DSU is a 56/64 Kbps synchronous DSU/CSU with one or four asynchronous ports and synchronous PPP or frame relay translation. The PPP-SR-DSU translates the synchronous protocols from the host router to asynchronous PPP and passes that to the async com ports of the remote PC's.

The unit is also available without the internal DSU, designated as the PPP-SR-01 one port unit and the PPP-SR-04 four port unit. Without the internal DSU, the PPP-SR can be connected to ISDN terminal adapters or fractional T1 channels at speeds up to 128 Kbps.
The PPP-SR-DSU negotiates the link with the computer and router as follows:

• The PPP-SR-DSU responds to the computer's AT modem commands with the appropriate "OK" and "CONNECT" responses.
• The PPP-SR-DSU presents "Login:" and "Password:" prompts as required by most async PPP dialing programs, and expects a carriage return response.
• The PC then negotiates the Local Control Protocol (LCP) and the IP Control Protocol (IPCP). After the negotiation is completed, the PC is on line.

The PPP-SR-DSU is easy to install and operate. Controls on the unit include the loopback push button, a switch to select line driver or phone company clock and a separate management/setup port. The Setup switch is used to access the management port from the user's PC port. The minimum number of controls and comprehensive indicators make installation and troubleshooting easy. Diagnostic aids built into the PPP-SR-DSU include LED indicators and loopback capabilities.

The hardware cost savings provide a compelling reason to use the PPP-SR-DSU. It is especially cost effective where a number of PPP synchronous digital channels are delivered to the phone company via DS-0's and T1 access multiplexing, or via frame relay. The PPP-SR-DSU is a very cost effective alternative to ISDN. In many areas, phone companies charge ISDN users per minute usage rates. At the end of month, ISDN charges for even 8am to 5pm operation weekdays can total hundreds of dollars. A dedicated link using the PPP-SR-DSU is often the more cost effective alternative.

SPECIFICATIONS

General

Rates: 56/64 Kbps synchronous (64 Kbps DSU to ship 9/97)
Async port rates to 57,600 bps
Application: Point-to-point
Facility: 56/64 Kbps Dataphone Digital Service (DDS) or equivalent, Line driver mode for customer owned 4-wire circuit. Supports frame relay at 56/64 Kbps

Indicators (front panel)

Power, Activity, Line Error, Modem Ready, Port 1 Setup, Loopback
DSU Led's: TxD, RxD, RTS, CTS, DCD, Test
 

Controls

Front panel push button for loopback
Side door accessible firmware cartridge for installing firmware upgrades
Rear panel switches for master or slave clock, RTS forced on or DTE controlled
Responds to telco current reversal loopback and non-latching pattern loopback.
Setup via the "Port One Setup" or via the rear panel setup port

Telco

Interface: DDS bipolar return to zero
Connector: 8-wire RJ-48S

Data Port

Interface: RS-232, V.24, speeds up to 57,600 bps
Connector: RJ-45 per EIA/TIA 561 pin outs

Physical/Electrical

Power requirements: 120 VAC,
60 Hz, 18 Watts
10 1/4" x 9 3/4" x 2 1/4"
One pound

Rear view of DCB PPP-SR01-DSU
 

Application

see other DCB pages