Looking at some documentation, I see that an Adva FSP150/BT-/CP/GIG/2AC is shown as measuring 439 mm wide by 43 mm high by 269 mm deep.
The rack mounting brackets are described as "extended", as they set the unit further back in the rack to allow sufficient clearance for the front connections.
I don't have access to one mounted in a rack but comparing the above dimensions to a free-standing unit, I suspect that the above quoted depth of 269 mm must include the extended mounting brackets.
Edited to add: Looking in the definitive Adva FSP150CP User Guide I see --
The chassis is an alloy steel case which houses the entire FSP 150CP system.
The dimensions of the chassis are:
• Height, 1U; 44mm
• Width, without mounting brackets; 433.2mm
• Depth, without International Electrotechnical Commission (IEC) and optical
The depth allows the chassis to fit into a 300mm deep ETSI cabinet.
The chassis may be positioned as a standalone unit or it may be rack or wall
mounted. Adaptation to rack or wall mounting is possible by using mounting
brackets and separate removable mounting brackets are available for:
• 19” rack mounting
• 23” ETSI rack mounting
• Recessed rack mounting brackets are also available for 19” and 23” ETSI racks in
order to ensure that optical fibre bend radius is maintained when installed in
some cabinets with doors.
• wall mounting.
All brackets are designed to be screwed to the sides of the chassis and the screws
supplied have European threads.
Edited by burakkucat (Mon 21-Oct-19 00:50:06)