Q1 .How many bytes of Application layer header ?
Data(200 bytes) +AP layer header(??) + TCP header(20 bytes) + IP
header(20 bytes) + Ethernet (14 bytes) + Pad(4 bytes)
I do not know the AP layer header.
Q2: MSG A header len (2bytes) + MSG A(100 bytes)=102 bytes,
MSG B headre len (2 bytes)+ MSG B(50 bytes) =52 bytes,
Could I combine MSG A+MSG B into one DATA (154 bytes) ?
Thank all !
> Dear guru :
> Anyone could tell me ,
>
> Q1 .How many bytes of Application layer header ?
> Data(200 bytes) +AP layer header(??) + TCP header(20 bytes) + IP
> header(20 bytes) + Ethernet (14 bytes) + Pad(4 bytes)
> I do not know the AP layer header.
There's no standard application layer header, it depends on the
application protocol. Many protocols don't even have a header, they're
just text streams, such as SMTP or TELNET.
> Q2: MSG A header len (2bytes) + MSG A(100 bytes)=102 bytes,
> MSG B headre len (2 bytes)+ MSG B(50 bytes) =52 bytes,
> Could I combine MSG A+MSG B into one DATA (154 bytes) ?
It depends on the protocol. If it's a datagram protocol, there's often
a requirement that each message be in a separate datagram. If it's a
stream protocol, and uses TCP as the transport, there's no way for the
application to tell how it was transmitted.
--
Barry Margolin, bar...@alum.mit.edu
Arlington, MA
*** PLEASE don't copy me on replies, I'll read them in the group ***
>
> > Q2: MSG A header len (2bytes) + MSG A(100 bytes)=102 bytes,
> > MSG B headre len (2 bytes)+ MSG B(50 bytes) =52 bytes,
> > Could I combine MSG A+MSG B into one DATA (154 bytes) ?
>
> It depends on the protocol. If it's a datagram protocol, there's often
> a requirement that each message be in a separate datagram. If it's a
> stream protocol, and uses TCP as the transport, there's no way for the
> application to tell how it was transmitted.
[ray] It is datagram protocol. Thanks !