This read-only Gauge reports the information transfer speed, in bits per second, negotiated for this connection when calling the peer, with detailed media-specific parameters such as ISDN information type extracted elsewhere; a value of zero means the transfer speed is unknown. An admin uses this to verify the actual negotiated line speed of a specific call leg rather than an assumed nominal rate. For example, a connection expected to negotiate at 64000 bps that instead reports 56000 bps here would alert the admin to a lower-than-expected connection speed on that call.