Description of Connection Types on the FRSM

Command and Response Mapping

The FRSM provides command and response mapping in both directions:

•In the Frame Relay-to-ATM direction, the FRSM maps the C/R bit of the received Frame Relay frame to the CPCS-UU least significant bit of the AAL5 CPCS PDU.

•In the ATM-to-Frame Relay direction, the FRSM maps the least significant bit of the CPCS-UU to the C/R bit of the Frame Relay frame.

Translation and Transparent Modes

Each service interworking (SIW) connection can exist in either translation or transparent mode. In translation mode, the FRSM translates protocols between the FR NLPID encapsulation (RFC 1490) and the ATM LCC encapsulation (RFC 1483). In transparent mode, the FRSM does not translate. Translation mode support includes address resolution by transforming address resolution protocol (ARP, RFC 826) and inverse ARP (inARP, RFC 1293) between the Frame Relay and ATM formats.

Frame Forwarding

You can configure an individual port for frame forwarding. Frame forwarding is the same as standard Frame Relay except that the FRSM:

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Does not interpret the two-byte Q.922 header.

Maps all received frames to a specific connection if it exists, otherwise it discards the frames.

Does not map between DE and CLP or between FECN and EFI.

Does not support statistics for “Illegal header count” or “Invalid DLCI.”

Does generate statistics for “Discarded frame count due to no connection.”

ATM/Frame-to-User Network Interface

All FRSMs support the ATM Frame User-to-Network Interface (FUNI). When a frame arrives from the FUNI interface, the FRSM removes the 2-byte FUNI header and segments the frame into ATM cells by using AAL5. In the reverse direction, the FRSM assembles ATM cells from the network into a frame by using AAL5, adds a FUNI header to the frame, and sends it to the FUNI port.

Loss Priority Indication

The FRSM maps the loss priority indication for both directions:

•In the FUNI to ATM direction, the FRSM maps the CLP bit in the FUNI header to the CLP bit of every ATM cell that it generates for the FUNI frame.

•In the ATM-to-FUNI direction, the FRSM always sets the CLP bit in the FUNI header to 0.

Congestion Indication

The FRSM maps congestion indication in both directions:

•In the FUNI-to-ATM direction, it sets EFCI to 0 for every ATM cell it generates by segmentation.

•In the ATM-to-FUNI direction, it sets the CN bit in the FUNI header to 1 if the EFCI field in the last ATM cell of a received, segmented frame is 1. The two reserve bits (the same positions as C/R and BECN in Frame Relay header) are always 0.

6-26Cisco MGX 8850 Installation and Configuration, Release 1.1.00, Part Number 78-6186-02

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Cisco Systems MGX-FRSM-2T3E3 manual Frame Forwarding, ATM/Frame-to-User Network Interface, Command and Response Mapping
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MGX-FRSM-HS2, MGX-FRSM-2T3E3, MGX-FRSM-2CT3 specifications

Cisco Systems is a leader in networking technology and infrastructure, providing solutions that drive innovation and efficiency for businesses worldwide. Among its diverse range of products, the MGX series stands out as a pivotal component for the network-centric era, especially with models like MGX-FRSM-2CT3, MGX-FRSM-2T3E3, and MGX-FRSM-HS2. These modules are primarily designed for the MGX 8800 series routers, facilitating efficient traffic management and service delivery.

The MGX-FRSM-2CT3 is a versatile module that supports two T3 connections. It allows network operators to seamlessly integrate high-capacity circuit-switched and packet-switched data on a unified platform. This versatility is crucial for service providers looking to enhance their bandwidth offerings while ensuring reliable performance across voice, video, and data applications.

In contrast, the MGX-FRSM-2T3E3 module caters to operators needing E3 support. This feature allows for efficient data transport over a broader bandwidth, catering to European standards. The E3 configuration is vital for service providers operating in Europe or regions that utilize E3 technology prominently.

The MGX-FRSM-HS2 module is another significant offering, designed to accommodate the increasing demand for high speed and high capacity. It supports higher-order TDM and packet technologies, enabling operators to implement advanced services such as VoIP, video conferencing, and other data-intensive applications. This module provides scalability and reliability, making it ideal for next-generation networks.

All three modules leverage Cisco’s advanced switching and routing technology, ensuring optimal performance and minimal latency. The integration of Quality of Service (QoS) features allows network administrators to prioritize traffic types effectively, ensuring mission-critical applications receive the necessary bandwidth.

Additionally, these MGX modules support various signaling protocols, enabling interoperability with existing network infrastructure while also facilitating the migration to newer technologies. They play an essential role in modernizing telecom networks, allowing service providers to adapt to changing market demands and technology landscapes.

In summary, the Cisco MGX-FRSM-2CT3, MGX-FRSM-2T3E3, and MGX-FRSM-HS2 modules are key components for businesses looking to enhance their networking capabilities. With their robust support for T3 and E3 technologies, high scalability, and advanced QoS features, these modules empower service providers to deliver a wide range of services, drive innovation, and meet the growing demands of users in an increasingly connected world.
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