Unidirectional Lightweight Encapsulation (ULE) Next-Header Registry 2005-09-13 2008-08-28 The range 512-1535 is also assigned for Optional Extension Headers. IANA does not allocate numbers in this range. The values are derived from the combination of a registry entry in the range 256-511, and the corresponding H-LEN values specified in each registry entry . Mandatory Extension Headers (or link-dependent type fields) for ULE (Range 0-255 decimal) Expert review or RFC Required 0 Test-SNDU 1 Bridged-SNDU 2 TS-Concat 3 PDU-Concat 4-199 Unassigned 200 LL_RCS_FEC_FDT EN 301 790 V1.5.1 201-255 Unassigned Optional Extension Headers for ULE (Range 256-511 decimal) Expert review or RFC Required 256 Extension-Padding 1-5 257 Time-Stamp 3 258-449 Unassigned 450 LL_RCS_FEC_ADT 4 EN 301 790 V1.5.1 451 LL_CRC32 3 EN 301 790 V1.5.1 452-511 Unassigned Laurence Duquerroy mailto:Laurence.Duquerroy&esa.int 2008-08-28