Hi I am new to the DataCom related protocols, I have small confusion in IPv4 and TCP headers. All we know IHL ( IPv4 Header length field in IPv4 header) and ataOffset( field in TCP header) are four(4 bit) bit fields. IHL ------> IHL is the Total IPv4 header length, maximum is 15 ( 15x4 = 60 bytes) ----refer RFC 791 DataOffset ------> DataOffset is total TCP header size ( in simple words) , maximum is 15 ( 15x4 = 60 bytes) ----refer RFC 793 >From above two, combined TCP/IP header maximum length is 120 bytes. But in RFC 1144 (page 13) , it was defined as 128 bytes. Is it correct? If so please clarify the same. If I am wrong please correct me. Thanks in advance. With Kind Regards, Ramana Divvi. *************************************************************************** This message is proprietary to Future Software Limited (FSL) and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error, please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. FSL accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus. ***************************************************************************