Patent ID: 7787420

Claim:
A method for negotiation of at least one parameter for use in the operation of a protocol that controls data transmission between first communication units and third communication units via second communication units, said protocol operated by protocol entities in said first and third communication units, said method comprising: transmitting, in case that it is possible that an association of a first communication unit with a second communication unit that is associated with a third communication unit of a first type may be changed to an association of said first communication unit with a second communication unit that is associated with a third communication unit of a second type, wherein said third communication unit of said first and second type require different choices of said parameter, at least one negotiation message containing a value for said parameter from a protocol entity of said first communication unit to a protocol entity of said third communication unit of said first type or from a protocol entity of said third communication unit of said first type to a protocol entity of said first communication unit prior to said change of associations; wherein it is checked by a protocol entity in said first communication unit or in said third communication unit of said first type whether it is possible that said data transmission between said first communication unit and said third communication unit of said second type is a multi-link data transmission that requires a definition of a re-sequencing timer as said parameter for said protocol; and whether a value for said re-sequencing timer is available as a basis for negotiation.