Modulo

is the number of values used in X.25 level 2 sequenced packets. The actual frame num- bering is 0–7for modulo 8 and 0–127for modulo 128.

Maximum LAPB Window Size

is X.25 value K, the maximum number of sequentially numbered I-frames that can be waiting for acknowledgment. If this number is exceeded, no more frames will be transmitted until an acknowledgment is received. A larger value allows faster throughput.

N2 Retransmit Count

is X.25 value N2, the maximum number of times the node will attempt to send an I- frame after a Retransmit Period expiration. A larger value for this parameter increases the probability of an eventual correct transfer between DTE and DCE, but a smaller value permits faster detection of a permanent error condition.

T1 Retransmit Period

is the length of time before re-transmission of an I-frame if the previous transmission is not acknowledged. If the period expires, the SmartSwitch software will reset the timer and transmit a supervisory frame demanding immediate acknowledgment. Also, the Maximum Retransmissions (see that entry) counter will be incremented. The default value of 2000 ms allows avoidance of unnecessary retransmission of frames that have merely been delayed.

T2 Wait Ack Period

is the length of time the node will delay acknowledgment of a received I-frame if there is no outgoing I-frame to be sent. If during this period the node receives an I-frame for transmission, the acknowledgment will be sent with it, and the delay timer will be reset.

T3 Link Alive Period

is the length of time after which the node will poll its counterpart if there is no data transfer.

Logical DCE

defines the port as (if Y) logical DCE or (if N) DTE. The port must be configured as the opposite of the device at the other end of the connection.

Logical and physical DCE/DTE are independent of each other (e.g., a port can be a physical DCE and logical DTE).

Generate Clock

specifies whether the port will generate the clock necessary to synchronize traffic over the link. If the port is a physical DCE (determined by the port's I/O cable interface), configure Generate Clock as Y, since the physical DCE generates clock. If the port is DTE, configure Generate Clock as N.

Rcv Clock (TT) from DTE

allows the clock to be looped back from the DTE using the TT (Terminal Timing) signal, which can be helpful on high-speed lines. Generally, if the local interface is physical DCE and the line speed is above 256 Kbps, this parameter should be set to Y. (Make sure the remote DTE is configured to provide the terminal timing.)

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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.

Lastly, the FRX1800, designed for small to medium businesses, focused on simplicity and ease of use while still incorporating powerful network management capabilities. Its user-friendly interface made it accessible for organizations lacking extensive IT resources. The FRX1800 provided essential functionalities such as Integrated Layer 2 switching and routing, network monitoring, and basic security features, ensuring that even smaller companies could maintain efficient, reliable networking without overwhelming complexity.

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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