Multisite and global organizations today are facing several unique Wide Area Network (WAN) challenges: the need to provide employees with instant access to centrally located information, the requirement to continuously back up and replicate mission-critical data to centrally managed data centers, the desire to provide satisfactory experience for IP phone and video communication, and the mandate to control bandwidth costs without sacrificing application availability and performance.The Network Capacity Expansion System (NCE) is designed to help organizations address these challenges. Cisco NCE is a transport layer Performance Enhancing Proxy (PEP) that increases the amount of available bandwidth at small to midsized branch offices and remote locations. It is designed to cost-effectively accelerate data transfer over the WAN by overcoming bandwidth and latency limitations. With NCE, multisite organizations get more data through and more value out of their existing WAN links.Building on the strengths of the award-winning Cisco Integrated Services Routers (ISRs), Cisco NCE is a small-footprint cost-effective module that transparently integrates into the ISR and natively uses capabilities of Cisco IOS software.Cisco NCE acts as a transparent PEP that terminates sender's TCP session locally, compresses and bundles the sender's data, sends the data to a remote peer encapsulated in a Stream Control Transmission Protocol (SCTP), unbundles and decompresses the data, and establishes a TCP session remotely to deliver the data to its destination.For remote and mobile sites, NCE is available in the Advanced Integration Module (AIM) form factor that is supported on all the modular ISRs. There are two AIM configurations differing by the amount of outbound bandwidth supported.Cisco NCE is a symmetric solution that requires a pair of peer devices between end nodes. Each NCE module is capable of simultaneously increasing throughput for multiple peers, allowing hub-to-spoke and meshed deployments. For central office (headend) aggregation, NCE is available in the Network Module Extended (NME) form factor.