TPKT Header (Q6)

The information in this article applies to:

The second octet of the TPKT header is "reserved." Its value is not defined in the current version of TPKT. On the receive side, you should not require it to be any particular value--ignore it. On the transmit side, set it to 0, because, alas, some vendors incorrectly expect it to be 0 and throw out control packets whose second octet is not 0. UPDATE: As of H.323v3, an EP shall set this octet to 0.

TPKT is defined in section 6 of RFC 1006.