o incompatible data sizes The level 2 link service provider has not been configured for a sufficiently large data size. The level 2 link service data size must be at least 260 and at least the DTE maximum packet size +4. o incompatible profiles There is a mismatch between the x25 protocol dte profile and the link service provider profile. o insufficient information inbound dte class, link service provider or x25 address characteristics necessary for the successful completion of the operation has not been set. o link service provider error Level 2 link service provider has flagged an error. o link service provider in use Another network layer entity is already using the specified link service provider. o no such link service provider The link service provider specified in the DTE does not exist.