sentences:  Edge switches, servers or PCs see the two aggregate switches as one large switch.This allows any vendor's equipment configured to use the IEEE 802.3ad static link aggregation protocol to connect to both switches and take advantage of load balancing, redundant connections.The IST protocol was developed by Nortel (now acquired by Avaya, which is now acquired by Extreme Networks) to enhance the capabilities of Link aggregation, and is required to be configured prior to configuring the SMLT, DSMLT or R-SMLT functions on the two aggregate (core, distribution, or access) switches.