This counter tracks the total bytes received from the remote client over this session, counted at the wire before the gateway attempts to decompress the payload. Because the desc specifies the count happens pre-decompression, an admin comparing this to post-decompression application-level traffic can estimate how much compression the client is actually achieving on the link. A session moving 50 MB of on-wire compressed data that decompresses to 150 MB of application data would indicate roughly 3:1 compression in effect.