Transmission of a tributary in synchronous mode at the level of a link of a data network

A device for the transmission of at least one tributary in synchronous mode at the level of a link of a data network, comprising:

• said tributary comprising at least one frame in the SDH or SONET format, said frame comprising at least one payload envelope area and one transport overhead area, said payload area comprising at least one payload and load supervision data related to the payload, said transport overhead area comprising at least transport supervision data related to transport and an area of fixed patterns comprising fixed patterns;
• said device comprising:
• a frame modifier operable to generate a modified frame;
• a transmitter operably transmitting said modified frame;
• a storage operably storing the transport supervision data;
• a deleter operably deleting part of said fixed patterns in said fixed pattern area;
• a recorder operably recording the positions of said part of the fixed patterns deleted;
• and
• an inserter operably inserting the transport supervision data at the level of said positions in said area of fixed patterns.

A method for transmitting at least one tributary in synchronous mode at a link of a data network, said method comprising:

• (a) modifying a frame so as to create a modified frame, said frame including at least one payload envelope area and one transport overhead area, said payload envelope area including at least one payload and load supervision data related to said payload, said transport overhead area initially including at least transport supervision data related to transport and an area of fixed patterns;
• said modifying further comprising:
• (i) recording the initial transport supervision data;
• (ii) introducing a delay to the frame;
• (iii) removing part of said fixed patterns;
• (iv) determining positions of said part of said removed fixed patterns;
• (v) inserting the stored initial transport supervision data at said positions in said area of fixed patterns;
• (vi) inserting new transport supervision data in the transport overhead area in place of the initial transport supervision data, said tributary including at least one frame in one of a SDH format and a SONET format;
• and
• (b) transmitting said modified frame.