Frame Forwarding, Loss Priority Indication

Chapter

Frame Relay Service Modules (FRSMs)

ATM to Frame Relay Direction

The least-significant bit of the CPCS-UU is mapped 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 (in ARP, RFC 1293) between the Frame Relay and ATM formats.

Frame Forwarding

The FRSM card can be configured as “Frame Forwarding” on a port-by-port basis.

Frame forwarding operates the same as standard Frame Relay except

•The 2-byte Q.922 header is not assumed/interpreted.

•All frames received are mapped to a specific connection if it exists. Otherwise, the frames are dropped.

•No DE/CLP or FECN/EFI mapping is performed.

•“Illegal header count” and “Invalid DLCI” statistics are not kept.

•“Discarded frame count due to no connection” statistic is kept.

Frame-based User-to-Network Interface (FUNI)

All FRSMs support the ATM Frame-based 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

Loss Priority Indication mapping is provided in both directions.

FUNI-to-ATM Direction

The CLP bit on the FUNI header is mapped to the CLP bit of every ATM cell that is generated for the FUNI frame.

ATM-to-FUNI Direction

CLP bit in the FUNI header is always set to 0.

Congestion Indication

Congestion Indication mapping is provided in both directions.

FUNI-to-ATM Direction

EFCI is set to 0 for every ATM cell generated by the segmentation process.

	Cisco MGX 8220 Installation and Configuration
4-6	Release 5.0, Part Number 78-6430-03 Rev. D0, November 2003

MGX 8220 specifications

The Cisco Systems MGX 8220 is a versatile, high-performance media gateway that has become an integral component in the telecommunications infrastructure. Designed to facilitate the transition from traditional circuit-switched networks to advanced packet-switched environments, the MGX 8220 supports a wide array of voice, video, and data services, making it an essential tool for service providers and enterprises seeking to enhance their network capabilities.

One of the key features of the MGX 8220 is its robust signaling and media processing capabilities. Equipped with support for both Voice over IP (VoIP) and traditional telephony protocols, this gateway enables seamless integration of different communication formats. It boasts a modular architecture, which allows for the addition or removal of various line cards to meet changing demands and technology advancements. This modularity provides operators with the flexibility to scale their services without significant overhauls to their existing infrastructure.

The MGX 8220 is capable of delivering high-density media handling for a multitude of services. With its support for ATM and IP networks, the gateway can handle TDM (Time-Division Multiplexing) to packet voice conversions efficiently. It is designed to optimize network resources by dynamically allocating bandwidth based on traffic requirements, thus ensuring efficient use of network resources and improved performance.

Another significant characteristic of the MGX 8220 is its enhanced quality of service (QoS) features. This capability ensures that voice and video traffic is prioritized appropriately, minimizing latency and jitter while maximizing overall call quality. By employing sophisticated traffic management techniques, the MGX 8220 can deliver a superior user experience, which is critical for any service provider aiming to offer competitive communication solutions.

Furthermore, the gateway includes built-in security features to protect against unauthorized access and ensure the integrity of sensitive data. This includes encryption for voice and video transmission, as well as support for secure signaling protocols.

Overall, the Cisco Systems MGX 8220 stands out as a comprehensive media gateway solution, providing essential functionalities for modern communication needs. Its combination of modularity, high-density processing, effective QoS management, and security features makes it a compelling choice for organizations looking to modernize their telecommunications infrastructure while ensuring reliability and performance. As businesses continue to evolve and demand more from their networks, the MGX 8220 offers a pathway to future-ready communications.

Cisco Systems MGX 8220 manual Frame Forwarding, Frame-based User-to-Network Interface Funi

Models: MGX 8220