However, SIS is not effective on a wide area network (WAN). A new WAN solution called LIN, or local instance networking, was developed. It is designed as an answer to these demands. LIN uses data reduction like SIS to prevent data from being processed twice. By applying this at the network level, common instances can be made across several applications for peak effectiveness. When LIN is combined with SIS, companies can use data reduction to boost storage capacity and speed up applications across a WAN.

LIN works by examining the data flowing at each point of the connection, for instance, at each side of a WAN, and stores a small invisible cache of the data used. Each day, the "Local instance" of these files is updated. LIN looks at each outbound packets and checks for a match at the opposite location. If there is a match, the packets are not allowed to travel, and a message is sent to use the local copy. If the data is modified, only the modified segment is transmitted, reducing the duplication of data.

LIN typically grants better accuracy than SIS when finding repetitive patterns. This is for several reasons. LIN inspects each byte, whether from Email, web transfer, or data communications, rather than large blocks. This means every application, even if it doesn't think it's own data is repetitive, will count as a hit. SIS doesn't have this feature, as if an application does not consider itself repetitive, SIS will overlook it.

LIN also works bi-directionally. This means that when data is delivered from one source to another, both sources are aware of what information is being sent, and can use references with each other to use the data, regardless of where the data is going or coming from.