SAN distance extensions with Alcatel-Lucent 1665 DMX

Overview

With today's increasing regulations and heightened concern with Business Continuity and Disaster Recovery, both large and small businesses must consider alternate storage architectures for distance extensions. Alcatel-Lucent 1665 DMX can provide a ubiquitous, flexible, highly reliable platform for both TDM and data-based transport, including voice, DSn Private Line, Ethernet, and storage (SAN) traffic.

Description

When SAN deployments began in corporations and colleges, it was to serve the needs of various, unique departments within a larger organization. The resulting situation, depicted in the figure below, is one of multiple SAN Islands made up of disparate technology with various management and transport requirements.

Figure 3-16: SAN islands today

There are three options available to connect SAN islands: IP, WDM, and SONET. IP is attractive due to its high availability, but it is non-deterministic and prone to packet loss. This makes IP incapable of providing both the capacity and reliability necessitated by enterprise requirements. WDM is not widely available for enterprises today, but is a good choice for large data center connectivity and those enterprises that require many storage ports.

SONET, on the other hand, is ubiquitously available and accepted as a data transport platform by business customers. It provides the most attractive balance of QoS and capacity for small to large-sized Enterprises running both synchronous (disk mirroring) and asynchronous (data replication/backup) applications. With new technology such as GFP, VCAT, and LCAS, SAN over SONET enables simple deployment and traffic engineering for carriers, while ensuring efficient transport by way of low overhead byte count and flexible framing. Due to SONET's advanced protection capabilities it can guarantee little or no packet loss for SAN transport. Plus, given Ethernet's incorporation into SONET platforms, SAN management can be easily centralized and performed over IP. For reliability, capacity, and ease of deployment/management SONET is the clear choice when considering the creation of corporate and campus SAN extensions.

Application advantages

In addition to GFP, VCAT, and LCAS, 1665 products incorporate a full array of SAN interfaces on a single card to enable efficient SAN transport over SONET. The SAN card uses PTM (Pluggable Transmission Module) optics, to provide FICON, ESCON, and Fibre-channel interfaces. The same card can be used on both the Alcatel-Lucent 1665 DMX and Alcatel-Lucent 1665 DMXtend, enabling rollout of new services from the metro core to edge, where and when they are requested. It can be equipped with four 200Mbps ESCON ports or four 1Gbs, two 2Gbs, or a mix of one 2Gbs and two 1Gbs FICON/FC ports. The SAN implementation offers standards-based buffer-to-buffer credit management for long distance operations, sub-rate allocation of asynchronous FC traffic, and provisionable bandwidth levels.

Alcatel-Lucent 1665 DMX and Alcatel-Lucent 1665 DMXtend are the ideal platforms for SAN/SONET connectivity. They can easily connect various enterprise SAN islands no matter what protocol is used. The figure below is a network view of multiple SANs connected within the same building or business park, across a region and nation-wide.

Figure 3-17: 1665 product family SAN transport