This is not quite true. MSS can be set arbitrarily by the other end
of the connection, and if the receiver is on a link with bigger MTU,
or just wants things in big batches, it can set MSS up to 65535.
It's up to your own end to check both MSS and the link MTU and
decide what size segs to send down to IP. IP will fragment if
it gets something it can't send on the link in one frame.
1460 is 1500 minus 20 for the IP header and 20 for the TCP header -
Standard Ethernet data max is 1500, not 1460. For some special
applications (Bridge trunking) this can be expanded somewhat.
It would be a very bad idea to hard-code 1460 into any software
you're writing.
Barney Wolff
On Fri, May 11, 2001 at 02:45:10AM -0400, [EMAIL PROTECTED] wrote:
> Hi,
> This is regarding the size of data from TCP/UDP layer to the ip layer. The number of
>bytes sent from tcp layer to ip layer to send depends on the tcp MSS (maxium segment
>size).For an ethernet this size is 1460 bytes.
>
> Based on the above my understanding is this.
>
> a) Since MSS is 1460 bytes the maximum number of bytes sent from TCP to ip layer
>cannot exceed this value.
> b) The maximum sized packet that can be received by ip layer from ethernet device
>is 1460 bytes.
> c) In case the packet is fragmented at the sending end, at the receiving after
>reassembly the maximum packet size cannot exceed 1460 bytes.
>
> Please mail me if my understanding is correct.
> Also whether for ipv6 there is any change.
>
> regards
> ravi prasad
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