CSU/DSU Operating Mode

determines whether the attached modem connection can be normal or limited distance (LDM), where the distance depends on the wire gauge, number of splice points, and line speed. For example, 26 gauge wire and a line speed of 64K bps allows a distance of 15000 feet. Lowering the speed to 56K increases the allowable distance to 18400 feet . If 19 gauge wire is used, the distances can be multiplied by three.

RTS Control

if Constant means that RTS will always be asserted, and if External means that the CSU/DSU will control RTS.

Lowest/Highest Incoming/Two-Way/Outgoing Channel

are the ranges of logical channel numbers (LCNs) that subscribers can use for calls through this port. The valid values for each parameter are determined as follows:

Channel

Valid Values

Lowest Incoming

1 through Highest Incoming

Highest Incoming

Greater than/equal to Lowest Incoming

Lowest 2-Way

Greater than Highest Incoming

Highest 2-Way

Greater than/equal to Lowest 2-Way

Lowest Outgoing

Greater than Highest 2-Way

Highest Outgoing

Lowest Outgoing through 4095

Changing any parameter to a value that violates this order automatically changes any other values now in violation, specifying the first value(s) within the valid range. If any pair is not used, its constraints apply to the next higher or lower pair (whichever is appropriate) in the above list.

Flow Control Negotiation

is an optional X.25 facility that permits negotiation of the flow control parameters (packet and window sizes for either direction of data transmission) on a per call basis. If this parameter is set to N, the default packet and window sizes will be used. If set to Y, a packet and/or window size included in a call packet will be used. (If either is not included, the default for that parameter will be used.)

Throughput Class Negotiation

is an optional X.25 facility that permits negotiation of the throughput classes for either direction of data transmission on a per call basis. If this parameter is set to N, the default (Maximum Throughput Class) will be used. If set to Y, any throughput class included in a call packet will be used. (If a class for either direction is not included, its default value will be used.)

Local Charging Prevention

prevents calls (if Y) from being charged to this port. Incoming calls from the network with Reverse Charging specified will be rejected; outgoing calls will have Reverse Charging inserted if it is not already in the call packet.

Reverse Charge Acceptance

authorizes transmission of incoming calls that request the X.25 Reverse Charging facility. If this parameter is set to N and a call requests Reverse Charging, the call will not be transmitted.

Fast Select Acceptance

authorizes transmission of incoming calls that request the X.25 Fast Select facility.

Configuring X.25

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Cabletron Systems 1800 manual Channel Valid Values
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1800 specifications

Cabletron Systems, a leading player in network management and telecommunications solutions during the late 20th century, introduced several innovative products that played a crucial role in shaping enterprise networking. Among these were the Cabletron FRX6000, FRX4000, and the FRX1800, which delivered advanced features aimed at enhancing network performance, security, and scalability.

The Cabletron FRX6000 was designed as a robust multi-layer switch, ideal for large-scale enterprise environments. It supported extensive routing capabilities, allowing organizations to manage traffic efficiently even under heavy loads. The FRX6000 boasted high throughput rates and low latency, making it suitable for demanding applications. With support for various network protocols, including IP, IPX, and AppleTalk, its adaptability made it a versatile choice for diverse networking needs. Moreover, security features like VLAN support and Access Control Lists (ACLs) provided enhanced protection against potential threats.

Moving to the FRX4000, this model offered a balance between performance and cost-effectiveness. The FRX4000 maintained many of the essential features of its larger counterpart while catering to medium-sized enterprises. It provided Layer 3 routing and could handle multiple simultaneous connections, ensuring seamless communication across departments. The modular design allowed for easy upgrades, enabling businesses to expand their network infrastructure without significant overhauls. This made the FRX4000 an attractive option for organizations looking to optimize their network investments.

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All three models utilized advanced technologies, including a high bandwidth backbone and state-of-the-art switching architecture, to enable fast and reliable data transfer. They also supported Quality of Service (QoS) mechanisms, allowing businesses to prioritize critical applications and ensure consistent performance across the network.

In summary, the Cabletron FRX6000, FRX4000, and FRX1800 were pivotal in enhancing network capabilities, providing organizations with scalable, secure, and high-performance options tailored to their specific needs.
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