ISP Information:
This is the common combination of a fan attached to a heatsink that is placed in contact with a microprocessor that needs to be cooled. The heatsink draws heat away from the processor, and the fan expedites the removal of the heat by moving air across the heatsink. Faster airflow generally equals better cooling.
ISP Glossary:
Heatsink Fan - PAT - please, no email address, too much SPAM. Name is just fine!On Wed, 18 Feb 2004 19:56:01 -0800, none@none.com wrote: One of the things that has me concerned and hope others is what was listed in the article. That cable modem traffic is pinged or actually "Routed" off other cable modems, so that traffic can be handled more effectively as a huge LAN My questions is: 1) Where is the security for traffic on this network?Through obscurity, the most common kind (unfortunately)! There is astandard DOCIS that is supposed to only allow data through to your PCthat is addressed to your modem (supposed to prevent "sniffing"). 2) Why has the cable modem services industry not taken a lead to encrypt or block access of traffic not deemed for a particular router off-limits, so that it can be shared with another user???Cable modem services are very much like Ethernet -- everyone on thesame segment has all the data reaching the port on the back of theirequipment (the modem in this case). It is up to that equipment toignore all data not addressed to it.In theory, the company's router will prevent me from seeing your dataif we are on different segments of the network. But if we are neighborsbeing fed off the same set of wires, the data is coming into my house.The big difference between the cable network and the phone network isthat direct addressibility. With the phone, there is a set of wiresthat run from the phone company equipment to your house and only yourhouse (yes, I know they have SLC's, but your signal is pulled off atthat point and sent down wires only to your house). With cable, thereis one wire that supplies a segment (one or more city blocks) and asplitter on the pole or pedestal that pulls the signal for your house.They can apply electrical signal filters at that point to prevent youfrom seeing HBO if you don't pay for it. In some cases filters allowyou to see the signal.But those filters are stupid -- they know nothing about MAC or IPaddresses. The data flows into each house and it is up to yourequipment to determine what data should be seen by you.The older cable modems (and Ethernet cards on a regular network) can beplaced in "promiscuous mode" where all data would be transfered to theCPU rather than only those packets addressed to the specific MACaddress.Encryption is expensive, slows down the process, and makes it harderfor the technicians to investigate problems -- that's why the companiesdon't implement it. [TELECOM Digest Editor's Note: Although I do not know the particulars of this, I do know that Mr. Mike Flood, the general manager of Cable One, here in Independence told me 'that was all taken care of recently' when I asked him 'what prevents everyone on the cable from showing up in my Network Neighborhood, and the other way around.' I am sorry to say I did not understand his sort of technical explanation. Maybe some of you could explain it to me in simple words.It could be that Cable One went to DOCIS standard modems that preventpromiscuous mode. I don't know if there are any cable modems out theresmart enough to filter based on network port.- David
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