More On Meeting Your Bandwidth Requirements For Supply Chain Management Applications

As I pointed out in a previous article, Supply Chain Management (SCM) is a compelx animal. The key to a successful SCM implementation is a clear understanding of the business objectives and business requirements of the company the SCM primarily supports.
This often includes a number of legacy systems which need to be integrated into the solution. From this will come the technical objectives to be met and the technical requirements that frame the solution. Only then will the commmunication requirements for bandwidth capacity, reliability, resiliancy, latency, security, and expandability be meaningful.Here's just 2 such technical aspects.....Frame RelayFrame relay initially had several advantages over the aletrnative solutions for SCM and other multi web site and multi company communications networks.The first advantage was with circuit costs.
For a multi web site network, the traditional aprpoach was a large number of point to point circuits. Each circiut required a router port, a CSU, and often a circuit monitoring module. With milage based pricing, each circuit represented a significant recurring cost on top of the initial hardware cotss.
Router sizing was often a factor of ports supported rather than performance capability.Frame relay exchanged the point to point circuit costs with an access circuit, typically at less than 1/10th of the cost.

With port speeds from DS0 to DS3, multiple sites could be connceted with a single port at each web site. A partial or full mesh, even with full redundancy, could be accomplished with really few router potrs and CSU at each web site. This represented significant capital savings.Using fractional T1 and T3 on the access circuits, frmae relay made expanding capacity between sites relatively painless. Port changes within the frame relay provider's network was often a configuration change. Expanding the actual circuits was typically a configuration change on the CSU and DACS.Adding new sites was often accomplished with physical changes at the new web site only. The new PVC across the frame relay network and at the existing site(s) was a configuration change.
Depending on the routers used and the rotuing protocol implemented, this might be accomplished without a maintenance window.The PVC approach allowed for additional security. A given location could be directed to a specific port within the DMZ, limiting the exposure of one's own network to other vendors within the SCM network.

Firewalls at each end allowed each company to control its own security.

The farme relay network was vulnerable to external monitoring at really few points, and the relationship of PVC traffic to specific customer required specific network design information.Frame relay offered the ability to have a disaster recovery web site support multiple locations. PVC between the disaster location and other locations could be defined in the configuration, allowing dynamic implementation of the diasster recovery network.As a circuit protocol, frame relay functions independent of other protocols. This segmentation allowed IPX, IP, SNA, and other sytsem communications protocols to be implemented over the same paths. If desired, each of thsee could have its own PVC and bandwidth, or they could all operate over a common path. Finally, the bandwidth and performance could be established specifically to web site pairs on a PVC basis.For a vendor that participated in multiple SCM networks, frame relay represented real cost savings. Instead of a new circuit for each network, a PVC colud be established. Instead of 6 week circuit installation delays, service could be established in hours.----So why the past tense?