Browse Prior Art Database

CONSTANT BIT RATE TRAFFIC OVER FLEX ETHERNET

IP.com Disclosure Number: IPCOM000248467D
Publication Date: 2016-Dec-02
Document File: 11 page(s) / 14M

Publishing Venue

The IP.com Prior Art Database

Related People

Gilberto Loprieno: AUTHOR [+3]

Abstract

Described herein are techniques that provide constant bit rate transportation via any protocol over Flex Ethernet (Flex-E) (e.g., Common Public Radio Interface (CPRI), Serial Digital Interface (SDI) video, Fibre Channel (FC) 16G/32G/128G, etc.) in a reliable and inexpensive manner using existing optical technologies. The techniques involve a physical coding sublayer (PCS) adapting any protocol to Flex-E time slots and can leverage most of the Internet Protocols (IPs) already developed for Ethernet transport. Further provided herein are methods for adding additional features such as security, operations, administration, and management (OAM), and precision timing protocol (PTP) via Flex-E Any-Protocol Inter-Packet Gap (FAP-IPG). The techniques are compatible with pluggable modules originally developed for high volume Ethernet traffic.

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CONSTANT BIT RATE TRAFFIC OVER FLEX ETHERNET

AUTHORS:

 Gilberto Loprieno
Davide Codella
Emanuele Giacometti

CISCO SYSTEMS, INC.

ABSTRACT

    Described herein are techniques that provide constant bit rate transportation via any protocol over Flex Ethernet (Flex-E) (e.g., Common Public Radio Interface (CPRI), Serial Digital Interface (SDI) video, Fibre Channel (FC) 16G/32G/128G, etc.) in a reliable and inexpensive manner using existing optical technologies. The techniques involve a physical coding sublayer (PCS) adapting any protocol to Flex-E time slots and can leverage most of the Internet Protocols (IPs) already developed for Ethernet transport. Further provided herein are methods for adding additional features such as security, operations, administration, and management (OAM), and precision timing protocol (PTP) via Flex-E Any-Protocol Inter-Packet Gap (FAP-IPG). The techniques are compatible with pluggable modules originally developed for high volume Ethernet traffic.

DETAILED DESCRIPTION

     Flex Ethernet (Flex-E) is a new technology developed to transport Ethernet at media access control (MAC) rates. Constant bit rate (CBR) traffic is grouped into 8x8 bytes (i.e., a block) and coded as 64b/66b (i.e., coded as data). These blocks are then transported over Flex-E. Typical traffic running at a given rate is divided by 5.15 Gbps in order to define the number of time slots required. The remaining bandwidth is then filled with an Enhanced Inter-Packet Gap (EIPG). If the CBR traffic has a frequency lower than approximately 5Gbps, CBR blocks are transported over a single time slot and the remaining bandwidth is filled with an EIPG. If the CBR frequency is higher than approximately 5Gbps, blocks are mapped over multiple time slots. For example, if CBR

Copyright 2016 Cisco Systems, Inc.

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traffic is 8Gbps, two time slots are required. For instance, Common Public Radio Interface (CPRI) line bit-rate option 4 (nominal rate 3072.0 Mbps) can be transported over a single time slot. However, CPRI line bit-rate option 9 (12165.12 Mbps) requires 3 time slots.

    Techniques provided herein involve mapping any traffic (e.g., CBR) over Flex-E time slots. As described herein, the size of each time slot is 8 bytes. Any protocol interfaces originally developed for high volume Ethernet traffic may be used to implement these techniques. In other words, these techniques involve re-using Flex-E, an emerging technology designed to transport any Ethernet traffic on existing low cost optical interfaces, to transport any traffic. For example, CPRI, Serial Digital Interface (SDI) for video applications, or 16G/32G/128G Fibre Channel (FC) may be transported over optical links using these techniques.

    By applying the methods described herein, Flex-E could be expanded to support any protocol. In an example, Flex-E has a structure based on an overhead followed by 1023 blocks, each one composed by 20 time slots. Each time slot is transporting a code- word of 8 b...