This is the maximum number of nodes an X.25 call is allowed to pass through before reaching its destination. This acts as a loop-safety and network-design constraint on this multi-node X.25 network; an admin designing routing across a large mesh of nodes must ensure the maximum path length between any two nodes stays within this hop limit, or legitimate calls to distant nodes could be rejected as exceeding the hop count. For example, setting this to 8 would cause a call requiring 9 hops across a sprawling network topology to fail, forcing the admin to either raise the limit or restructure routing to shorten the path.