T2-Rcv Ack Timer, N2-Max LPDUs | Cabletron Systems 1800, FRX4000

SNA Status and Conﬁguration

If the T1 Timer expires and acknowledgments or responses are still outstanding, the link station will send one of the following, then restart the T1 Timer:

¥A Supervisory LPDU with the P bit set to BÕ1Õ to solicit remote link station status

¥Any Unnumbered LPDUs that were not responded to the Þrst time they were sent.

If acknowledgments or responses are still outstanding after the number of tries speciÞed in the N2-Max LPDUs parameter (see below), the link station will declare the link inoperative.

The value speciÞed for the T1 LLC2 Reply Timer should allow for any delays introduced by the MAC sublayer (e.g., queuing). The value is the amount of time in 100 millisecond units; the default value is 10.

T2-Rcv Ack Timer

This is the Receiver Acknowledgment Timer, used by the link station to delay sending an acknowledgment of a received Information LPDU. The timer is started when the LPDU is received, and reset when the acknowledgment is sent. If the timer expires before the acknowledgment is sent, it must be sent as soon as possible. The value is the amount of time in milliseconds; the default value is 100. The value must be less than the value for the T1-LLC2 Reply Timer (see above) to ensure that the remote link station will receive the delayed acknowledgment before the T1 Timer expires.

N2-Max LPDUs

This is the maximum number of times that an LPDU (including Information LPDUs resent after a checkpoint operation) will be sent following the expiration of the T1 Timer. The default value for this parameter is 8.

N3-Max Info LPDUs

This is the number of Information LPDUs that will be received by the local station before it sends an acknowledgment. This parameter is used in conjunction with the T2-Rcv Ack Timer to allow stations to reduce trafÞc. A counter is initialized to the value speciÞed, and is decremented by one each time a valid sequential Information LPDU is received. When the counter reaches 0, an acknowledgment is sent. The counter is reset whenever an Information or Supervisory acknowledgment LPDU is sent by the local station. The default value for this parameter is 1.

Tw-Max Out LPDUs

This is the maximum number of sequentially numbered Information LPDUs that the link station can have outstanding. The default value for this parameter is 1.

Bandwidth Allocation Group

This parameter assigns the LLC2 host to one of 16 Bandwidth Allocation Groups (BAG). The default value for this parameter is 0.

Conﬁguring SNA Ports

7-13

1800, FRX4000, FRX6000 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.

Cabletron Systems 1800 manual T2-Rcv Ack Timer, N2-Max LPDUs, N3-Max Info LPDUs, Tw-Max Out LPDUs

Models: 1800 FRX4000 FRX6000