Difference between "meg" amd "mbps"?

[724]

I am about to leave my University, and now have a house to move into. However, I have no idea what a good internet speed is. Of two sites that look rather ok, one offers "5.0 M" for $68 bucks a month and the other offers 'download speeds up to 1.5 Mbps" for $100 bucks per month. Now, I have no idea if 1 Mbps is equal too 1 M, but looking at the price difference would suggest that is not the case. Am I better off with the 5.0 M plan or the 1.5 Mbps plan?
To be clear, yes I do use a LOT of internet with several computers, a 360, PS3 and mobile devices.

[GOD]

Yes, for speed measuring purposes ISPs use (incorrectly) M instead of Mbps to represent the same.
5M is on the slow-ish side of fast internet, but it can handle a HD Netflix stream.

[rowlfe]

You will see all kinds of numbers and abbreviations. Suffice to say a DSL connection uses "megabytes per second" or "kilobytes per second" and cable broadband uses "megabits per second" however both use "mbps" or "mbs" most of the time. DSL uses bytes (1 byte = 8 bits) while cable (and wifi) uses bits. Ask each provider what those numbers MEAN in plain English. With DSL, the speed you get is guaranteed since DSL is a private line from your router in your home to the router at your ISP, no sharing of bandwidth with anyone else. Cable broadband is a party line and you share bandwidth with all of the other users. I have a 256K DSL line, which means 256 kilobytes per second. This is relatively slow as connections go, but then I do not stream video or have a game console. My DSL is equivalent to a 2mbps cable link (8 * 256K = 2.048 mbps). The thing about cable speed is you can't get it, ever, in practice. The speed you see is a theoretical maximum. The actual speed is variable and depends on how many users are on the party line with you. The more users, the slower everyone goes. This slowdown is called "the party line effect" and is a very real thing. The reason for the slowdown is two-fold. In essence, each user has a push to talk walkie talkie. You can listen or transmit, but not both at the same time. The access point at the cable "head end" for your ISP has a transmitter just as each user does, which means the access point is a bottleneck, since it can "talk" to only one user at a time. If there are 99 users on the line with you (your neighbors nearby), in effect, you get to talk for 1 second out of every 100. The other 99 users get their second and then the access point starts over. So, what happens is you get short bursts of data and you send short bursts of data and have to wait for your turn to come around again. The second mechanism is interference from other users. When you want to talk, you listen to see if the line is clear and if it is, you push to talk and send data, then wait for a reply. When you get the reply, you can send the next block of data. No problem. If the line is busy, you wait and when it clears, you do the same thing. This time, the waiting period cost you some time, which lowers your throughput somewhat. The big problem arises when you are not alone waiting. When the line clears, you both key up and talk, but the signals interfere and the access point hears garbage. Your data went nowhere. So, after a timeout period without a reply, you do it again, and so does the other guy, and you collide again, and again, and again, trying to send the same block of data and failing. Finally one of you gets far enough out of sync that one of you keys up while the other is checking the line and wins, by taking the floor, forcing the loser to wait longer. This is called a traffic jam and the reason why it is so bad is because no one moves any data until it finally clears itself when a user (or the access point) grabs the floor. The more users waiting to talk means it takes that much longer for the traffic jam to clear. THAT is why you will be doing good to have as much as 1/3rd of the rated speed from cable in throughput. Speed is a constant since that is determined by the radio frequencies used. Speed is the rate data moves, while throughput is a quantity of data received or sent over time. Cable uses higher frequencies so their speeds are faster than DSL. What counts is throughput, which is a measure of a quantity of data over time. By the way, this same effect is seen with wifi (wireless access). The only difference is the cable system uses much higher frequencies and a wire to carry the signals from the access point to and from the users that are connected. The more users, the slower everyone goes. Bottom line, get the fastest service that you can afford. And then limit the devices on your LAN to as few as possible. The ideal and best case would be one computer running one application over wire to your router. Use wire instead of wireless where ever possible to avoid the party line effect that slows down wireless links. By the way, my 256K connection costs me $30/month. $15 to my phone company for the DSL and $15 for my ISP. I purchased my DSL modem so I could save on the monthly rental fee. $90 equals 18 months and it has paid for itself starting with month 19. But then, I live alone and I do not do any data intensive things like stream video or online gaming. My neighbor lives alone as I do, with a 7mbps cable connection and complains almost on a daily basis about his throughput dropping and turning into molasses in January during peak use hours such as after school and early evening after dinner, which are mainly when kids/families are online.

One last thing, cable and wireless providers will generally NOT admit that there is such a thing as "the party line effect" or they will poo-poo the idea and tell you it is not significant. If you can talk with a network engineer, the engineer WILL admit it. It is sales people who dismiss the party line effect as nonsense. I'm glad you asked this question. It shows your interest in knowing how stuff really works rather than just believing the sales hype. I hope I have provided you with enough knowledge so that you can avoid the hype and ask the right questions to get the answers you need so you can make an informed decision as to which is the better deal. As I said, my DSL is not exactly a speed demon, but at only $30/month it serves me well. My speed and throughput are guaranteed 24/7. The ONLY time I see any slowdown is when I visit a busy site with a lot of traffic and THAT is not the fault of my connection to the net. This is like the tortoise and the hare. "Slow and steady wins the race", but it won't do very well for video streaming or gaming.