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Thread ID: 38972 2003-10-23 10:15:00 8bits to 1Byte . . . whats a Packet worth? sc0ut (2899) Press F1
Post ID Timestamp Content User
185957 2003-10-23 10:15:00 whats a packet worth
is it a set amount?
sc0ut (2899)
185958 2003-10-23 10:21:00 Don't think so but there is a limit. ping = 32bytes doesn't it.

Cheers Murray P
Murray P (44)
185959 2003-10-23 10:49:00 A packet is used by the TCP/IP protocol. It doesn't have a pixed size IIRC. It's more to do with headers/footers/error-correction/etc has been put around the data.

Murray, check out the help on the ping command, you can change the size of the ping.
-=JM=- (16)
185960 2003-10-23 20:48:00 A packet can be any size you want. There is a limit on how big it can be before it's fragmented (chopped up into little bits as it goes across the interweb). This limit is called the mtu (max transmission unit) and will vary depending on what gadgets the packet must pass through eg LAN, Modem, Router, VPN etc) BIFF (1)
185961 2003-10-23 22:18:00 A message (data) can be any size you want, the protocol used, will determine what size the message will be split up into for sending, the packet (datagrams) is the split up version of the message as well as having some added information from the protocol for error checking, receiving and responding information.

So theoretically a packet can be any size, but there's a lot of factors you would have to consider.
Kame (312)
185962 2003-10-23 23:49:00 Its been a while since I've had to know this, but from what I recall...

Each IP packet has a header of 5 x 32bits. So I guess the lower bound would be an empty packet (no data) of 20B.

The header uses only 16bits to represent the length of the packet, so the maximum size of a packet is 2^16 = 64KB.


But as has been mentioned, the MTU is also a limit on size.
bmason (508)
185963 2003-10-24 00:07:00 Where did you get the idea that a byte is 8 bits?

8 bits is an octet.

I was using 6 bit "bytes" long before there were IBM PCs. I've seen 9 bits "bytes", too. Those were common on DEC minis. In Burroughs mainframes, there were even 12 bit "syllables".

I think the smallest allowable packet in Ethernet is 64 octets. That's to do with collision detection.
Graham L (2)
185964 2003-10-24 05:26:00 > Where did you get the idea that a byte is 8 bits?
>
> 8 bits is an octet.

Argh, now you just add more confusion X-(

Silly education providers not providing correct education.
-=JM=- (16)
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