This read-write Integer32 (1-100000, default 500 milliseconds) sets the maximum timeout used together with xgcpRequestTimeout and xgcpRequestRetries to compute the exponential retry interval for retransmitting unacknowledged XGCP messages, and it must be set greater than or equal to xgcpRequestTimeout. An admin cares because this value caps how long the exponential backoff for message retransmission is allowed to grow, directly affecting how long a lost XGCP command takes to finally give up retrying. For example, an operator on a high-latency link experiencing frequent unnecessary XGCP retransmissions would raise this maximum timeout so the exponential backoff can grow larger before retrying.