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Old Dec 2, 2006, 05:58 PM   #1
seattlemaclover
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Comcast Internet - Can I add a second Modem?

I have Comcast Cable Internet and am trying to figure out if I can add a second cable modem. I have one in my living room connected to my airport express and want to put a secon in the den directly connected my new 24" iMac. Does anyone know if this is possible?
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Old Dec 2, 2006, 06:23 PM   #2
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not sure if you can, there is prob an additional monthly charge. Stupid question why not just just connect the iMac over wireless?
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Old Dec 2, 2006, 06:30 PM   #3
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Yes, why not just connect the iMac via the signal from your Airport express?
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Old Dec 2, 2006, 06:38 PM   #4
seattlemaclover
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I want the added speed of a wired connection.
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Old Dec 2, 2006, 06:43 PM   #5
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Quote:
Originally Posted by seattlemaclover View Post
I have Comcast Cable Internet and am trying to figure out if I can add a second cable modem. I have one in my living room connected to my airport express and want to put a second in the den directly connected my new 24" iMac. Does anyone know if this is possible?
im going to say no without talking to comcast. You can't just plug in a modem and have it work. Comcast needs the MAC address of it. Also they use higher grade coax cables to keep out interference, which you probably don't have installed.

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I want the added speed of a wired connection.
their is no way your getting more speed over your cable modem that 802.11g, heck 802.11b, can handle.
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Old Dec 2, 2006, 06:43 PM   #6
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Quote:
Originally Posted by seattlemaclover View Post
I want the added speed of a wired connection.
There isn't any. An 802.11g connection is MUCH faster than the Comcast connection, it's definitely not the limiting factor. Wired connections are faster than wireless for a LAN, but not for internet.
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Old Dec 2, 2006, 06:47 PM   #7
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Originally Posted by seattlemaclover View Post
I want the added speed of a wired connection.
Airport Express transmits at speeds up to 54 Mbps. How fast is your cable Internet? 3 Mbps? Maybe 4? A cabled connection won't make your internet go any faster.
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Old Dec 2, 2006, 06:52 PM   #8
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Originally Posted by mduser63 View Post
There isn't any. An 802.11g connection is MUCH faster than the Comcast connection, it's definitely not the limiting factor.

Tell me if I am reading this right, but your comment implies that the comcast connection is not 802.11g.

Do I have this right?

What, in fact, is the Comcast conneection and how do I go about checking this out?

This is actually something I have been wondering about for a bit now. One of the things I was really excited about was when I heard that Stevo had snuck into the factory one late night and decided to start slipping 802.11n wireless chip sets in the new MBP. Does this addition make any difference if then if the wireless modem is 802.11g or less? I would have to think the answer is still yes, but only to a very minor degree, but I really don't know so I would welcome your thoughts.
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Old Dec 2, 2006, 07:44 PM   #9
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I use to be a Comacast installer and can answer this one.(Note: left the company mid-2004 but I'm sure not much has changed on the back-end of things)

Short answer:No
Long answer:It's possible, but.....

Brief explanation: This was a common thing I heard when I did hi-speed installs. Most people think 'One modem is fast then 2 must be faster', but that's not quiet correct. People think that if they have a modem for each computer that each one as a fastest connection possible. But if you think about it, both modems hook into the same cable that feeds your home from the pole(or underground line). They would both be connected to it via a splitter in your home. The internet signal is broadcast across the cable via a certain frequency bands. For example my area used the freq's around the 729MHz band for internet use. Even though there are in reality multiple channels/bands available(we had up to 3 in my area), your mulitple modems would be trying to use the same part of the 'pipe'(freq range) at the same time. Slowing down the speed across all of them. So to get equal speed over mulitple modems, you would have to have one 'drop' (physical cable feed) per modem going to your home from the 'tap'(were your cable line connects to the main line at the pole). Most cable company networks are only designed to have one 'drop' per residence to keep overhead costs down. Also on the network side of things, you can only have one active modem on an individual customer account. I believe this is a limitation of the software they use. If you try to add multiple modems on one account, none of them will be able to get a ip address because the 'headend'(backbone of the network) doesn't know which one is suppose to be active. In theory you could get mulitiple drops if your home was setup as a MDU(multiple dwelling unit-apartment), but more then likely they would not allow it or charge you a small fortune to do it.

For most use, your not going to max out your single connection anyways. That's why home networking is the most popular way to go. Just use your Airport Express to connect both computers to the modem. If you want a faster 'wired' connection, then look into wireing your home for ethernet. Then just share your internet over a wired router.(persoanl note: make sure you get a good one. my month and a half old linksys router went out about a week ago. seocond one in a year)

Hope this wasn't too long winded. Hope this helped some.

Edit: Speed wise, the cable modem speeds(3-8Mbps depending on area) means the speed of the conection of the modem to the internet. The 802.11 speeds(example-54Mbps) means the speed of the wired/wireless router connection to your computers. Meaning that your computer to computer home network will be faster then any of their connections to the internet.
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Last edited by Yoursh; Dec 2, 2006 at 07:50 PM.
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Old Dec 2, 2006, 07:50 PM   #10
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Quote:
Originally Posted by Yoursh View Post
I use to be a Comacast installer and can answer this one.(Note: left the company mid-2004 but I'm sure not much has changed on the back-end of things)

Short answer:No
Long answer:It's possible, but.....

Brief explanation: This was a common thing I heard when I did hi-speed installs. Most people think 'One modem is fast then 2 must be faster', but that's not quiet correct. People think that if they have a modem for each computer that each one as a fastest connection possible. But if you think about it, both modems hook into the same cable that feeds your home from the pole(or underground line). They would both be connected to it via a splitter in your home. The internet signal is broadcast across the cable via a certain frequency bands. For example my area used the freq's around the 729MHz band for internet use. Even though there are in reality multiple channels/bands available(we had up to 3 in my area), your mulitple modems would be trying to use the same part of the 'pipe'(freq range) at the same time. Slowing down the speed across all of them. So to get equal speed over mulitple modems, you would have to have one 'drop' (physical cable feed) per modem going to your home from the 'tap'(were your cable line connects to the main line at the pole). Most cable company networks are only designed to have one 'drop' per residence to keep overhead costs down. Also on the network side of things, you can only have one active modem on an individual customer account. I believe this is a limitation of the software they use. If you try to add multiple modems on one account, none of them will be able to get a ip address because the 'headend'(backbone of the network) doesn't know which one is suppose to be active. In theory you could get mulitiple drops if your home was setup as a MDU(multiple dwelling unit-apartment), but more then likely they would not allow it or charge you a small fortune to do it.

For most use, your not going to max out your single connection anyways. That's why home networking is the most popular way to go. Just use your Airport Express to connect both computers to the modem. If you want a faster 'wired' connection, then look into wireing your home for ethernet. Then just share your internet over a wired router.(persoanl note: make sure you get a good one. my month and a half old linksys router went out about a week ago. seocond one in a year)

Hope this wasn't too long winded. Hope this helped some.
hmm.. very interesting thank you for your valuable knowledge on cable co's.
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Old Dec 2, 2006, 07:51 PM   #11
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Edit: Accidental double post

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Old Dec 2, 2006, 11:59 PM   #12
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Quote:
Originally Posted by Aniej View Post
Tell me if I am reading this right, but your comment implies that the comcast connection is not 802.11g.

Do I have this right?

What, in fact, is the Comcast conneection and how do I go about checking this out?

This is actually something I have been wondering about for a bit now. One of the things I was really excited about was when I heard that Stevo had snuck into the factory one late night and decided to start slipping 802.11n wireless chip sets in the new MBP. Does this addition make any difference if then if the wireless modem is 802.11g or less? I would have to think the answer is still yes, but only to a very minor degree, but I really don't know so I would welcome your thoughts.
802.11g is a protocol for wireless networks. The Comcast connection itself is something entirely different (it's not wireless for one thing). I don't really know the details of the protocol, but it's definitely not 802.11g. 802.11n is another wireless protocol that is faster than 802.11g. However, any 802.11 protocol is going to be much faster than the cable internet connection, so distributing your internet connection to computers via wireless doesn't slow down your internet at all (as compared to a wired connection). I think where you're getting confused is in thinking that 802.11g is a general internet protocol when in fact it is specifically the protocol used for wireless local area networks.
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