carried in the auth_els the transaction identifier 19 contains an identifier used to relate together the messages that compose a particular authentication protocol which may be as previously described dh chap or srp or fcap the message payload 20 contains the actual authentication message carried by the auth_els the auth_els flags field 14 is the modification added by to the auth_els messages according to this invention referring to fig2 a table defining the auth_els flags field 14 of the els authentication message structure according to the present invention is shown the auth_els flags field 14 includes a fragmentation bit 30 which is either set u201c 1 u201d to indicate that u201c more fragments follow u201d or reset u201c 0 u201d to indicate that u201c no more fragments u201d follow in other words if the fragmentation bit 30 is set it means that the auth_els carries a fragment of a larger authentication message if it is reset it means the auth_els carries the last fragment of a larger authentication message or the entire message the auth_els flags field 14 includes also a one bit sequence number 32 which is used for error recovery as explained in greater detail below when a fragment of a larger.