using a network utility I noticed a large number of duplicate packets received. e.g 74964 packets received, 11230 duplicate packets receieved. Also 70931 acks/29400 duplicate acks. Is this normal or is it a bandwidth guzzler. BTW I use the internal v.90 56K modem. (normal connect speed 49333) TCP/IP settings are controlled by the OS but can be modified in the terminal window. Comments like buy a PC or get cable will not be considered helpful. Cheers, Steve

Your statistics do not look troublesome. I would not be worried. To lessen the amount of packets total, you can consider adjusting your Maximum Transfer Unit and default window size via an OSX equivalent of DRTCP (a Windows utility to adjust TCP/IP stack settings). Duplicate packets exist for lots of reasons. A lot of this is out of your direct control. Yes, it does take bandwidth, but that is partially the cost of the Internet. You have to renegotiate the connection (sometimes constantly) and resend packets. Duplicate ACKs are not uncommon, because an ACK is simply a procedural aknowledgement, not really a data payload. Consider that just as individuals often use the same greetings and responses, so do computers. This can happen many times as one packet is lost in a series or incomplete. Lost packets are increasingly uncommon in average Western network traffic. But any sort of bottleneck or load can result in the same packet to be sent twice. What really happens, not so much in specification as in practice, is that if the sender does not get a response in the expected period (a loosely calculated window of time), then it is faster to just send the packet again, rather than wait. It is much like me yelling "hello!" across a busy street. Rather than wait for you to stop, look around, and yell back, I can just repeat my yell. You may recieve both signals, but in the time it takes for me to determine reception of the first signal, we could already be talking. Expect lots of duplicate ACKs. These should naturally be more prevalent than duplicate data packets. Duplicate data packets depend on the type of packet as well. UDP, for example is a connectionless protocol, so naturally the sender will resend when in doubt everytime. TCP establishes a connection, but that requires overhead of extra packets as well. And finally, you are on dial-up and this means there some extra packets sent for your connection medium. For every network route at various times, you should expect varying numbers of duplicate packets.

Be aware, that a loss of 5% of packets sent is considered acceptable now days. The old internet specifications for routers call for them to send a reply back when they were too busy to handle a packet. Then new specifications require that they do not send back a busy type of response in this case, but just drop the packet, knowing that the source will resend after a timeout. They now consider lost packets an indication that the internet link(s) are overloaded. Sucks.