STRENGTH IN DIVERSITY
As I write this article in the last few days of 2006, carriers are scrambling to find network solutions to restore connectivity following the failure of several submarine cable networks as a result of the 26th December (UTC) earthquake off Taiwan. Yeom Woo Jong, of South Korea’s KT Corporation, summed it up for the New York Times: “This incident reminds telecommunications companies like us of the importance of acquiring alternative lines to ensure undisrupted services during an emergency.” There have been two significant shifts in the thinking of network planners over the last few years that hold implications for network security. One is the migration from protected to unprotected capacity as the predominant transport mode. The second is the move towards mesh network topologies. The move to unprotected capacity has been driven by the emergence of internet traffic as by far the largest consumer of bandwidth on submarine networks. As broadband penetration continues to grow and accelerating download speeds compound the impact on demand, the domination of internet traffic will only become more complete. Internet traffic, being packet based, does not require the virtually seamless transmission continuity demanded by voice networks and afforded by protected capacity. Planners have therefore increasingly demanded unprotected capacity, which provides more efficient utilisation of network resources and therefore lower costs.
By Robin Russell
Capacity at our launch back in 2001. Today, while protected capacity remains our flagship, the most popular product is FlexProtect™. This product offers customers the option to configure network protection as either: (a) One Protected path, where a protection path on the SDH ring is reserved to protect traffic on the service path in the event of failure (b) Two Non Pre-emptible Unprotected paths, where both paths are utilised to carry traffic and neither path is pre-empted by the other (c) One Protected path plus one Pre-emptible Unprotected path, where high priority traffic is carried on the service path and lower priority traffic is carried on the protection path, where it may be pre-empted in the event of failure of the service path. The third configuration is overwhelmingly the most popular with AJC’s customers, since it offers the same ultra-reliable transmission as traditional Protected capacity on the service path, with the bonus of additional throughput on the protection path at very acceptable availability. It is important to note the different availability for the different types of capacity (which are all in accordance with the ITU-T recommendations, G.841 being the most relevant).
Submarine networks have responded with changes to their product offerings. In the case of Australia Japan Cable (AJC), we offered only Protected 16