The associd field is set to all ones. The ethernet destination address may be set to the hardware broadcast address if it is not otherwise known.
Although conveying absolutely no semantic information these fields are all present and contain the expected values.
The payload contains a single cell. The format adopted is as displayed in table 2. Unfortunately some endian assumptions are made by this structure. Such fields have ``network endian''.
Table 2: FDL Meta Signalling Cell format
The communicating entities construct the VCIs from the associds in this structure and the ethernet addresses present in the frame header which carried this structure. Unfortunately there is an additional munging which must take place between that used in the control structure and that which must be present in the frame header.
Table 3: Associd present in Frame Header
Table 4: Associd present in Control Structure
There is no justification for this perversity.
The meta signalling commands used on EDL are identical to those used by all other current implementations of MSDL. They are therefore described in that generic document.