IP datagram de-encapsulation

An apparatus for reconstruction of a section transmitted in a plurality of packets, wherein the section comprises a plurality of fragments, wherein each of the plurality of packets includes a header and a payload, wherein the header comprises an integer continuity counter CC that counts lost packets of the plurality of packets, and wherein the payload includes at least one of the plurality of fragments, the apparatus comprising:

• a fragment memory adapted to store at least a portion of the plurality of fragments, the fragment memory comprising:
• a plurality of columns;
• and
• a fragment pointer FP pointing at a first column of the plurality of columns to receive a first fragment of the plurality of fragments, wherein the first fragment is received in a first packet of the plurality of packets;
• a frame memory adapted to store at least a portion of the fragment memory;
• and
• a de-encapsulator module configured to—
• maintain a shadow counter SC to track an expected value of CC and to initialize SC=CC, and enforce a predetermined consistency criteria of SC=CC,
• maintain a discontinuity counter DC, a missed fragment counter K,
• when the first packet is one of:
• received correctly, and
• includes an un-correctable error and CC=SC, then store the first fragment at the first column of the fragment memory pointed at by FP and then adjust FP and SC to respectively point at a second column of the plurality of columns to receive a second fragment of the plurality of fragments and the value of CC expected in a second packet of the of the plurality of packets;
• and
• when the first packet includes the un-correctable error and CC≠SC, to ignore the first packet.