Bytes is a read-only Counter32 giving the total number of bytes transmitted and received for this IP-to-IP conversation, combining both directions into one running count. Because it counts bytes rather than frames, this object tells an admin how much actual data volume a IP-to-IP conversation is pushing, which matters more than frame count when sizing bandwidth for large-file transfers, and — since this ipsb table duplicates the row layout of the MIB's iplb table but is sampled and indexed independently — a given pair can show different collection intervals in ipsb than it does in iplb. A IP-to-IP conversation that moves a small Frames count but a huge Bytes count (as with the pair 10.4.12.30/198.51.100.7) points to large packets, such as bulk transfers, rather than many small chatty ones.