1) These are available from Brookstone for $150...
2) Delcom Engineering has a "USB Visual Signal Indicator". This includes RED, GREEN, and BLUE LEDs, Piezo buzzer, 2 meter USB cable and USB powered circuit. The cost? $69.00 each... All you need to add is a globe...
If you want to play around with this stuff, Delcom Engineering also makes USB chips, cables, etc. and they make USB development board for $49.00 that you could you could use to build what ever you wish...
First off, some basics:
Channel = 65,536 (or 64k) bits of data both ways.
T1 = 24 channels.
DS3 = 28 T1's.
OC3 = 3 DS3's
OC12 = 12 DS3's
OC192 = 192 DS3's
Channels are also known as DS0's.
T1's are also known as DS1's.
DS3's are also known as T3's.
NOTE: In Europe T1's are called E1's and have 30 channels (DS3's are called T3's).
With this in mind, a full T1 can transmit 1,572,864 bits per second (or divided by 1,024 you get 1,536kbps) and receive 1,572,864 bits per second at the same time.
There are three components to a T1 (or a DS3): A local loop connection to you, a local loop connection to your ISP, and the interconnecting circuit. There are costs for all three parts.
BTW: T1's were (and still are) originally used for voice communications, and can have 24 phone conversations going on at the same time. Each conversation basically uses 8,192 8-bit digital samples per second to transmit voice traffic (CD's use 44,000 16-bit samples).
What the heck is a Frame-Relay T1?
Sometimes an ISP will sell you a Frame-Relay T1 instead of a true or full T1 (FYI: A true T1 has four wires, a frame-relay circuit has two.) Frame-Relay T1's are shared T1's - this basically means that they provide a certain amount of bandwidth and anything above that may or may not make it to the destination depending on how busy their network is at that point in time. This is usually set to 50% of the total bandwidth and is called CIR (Committed Information Rate).
After this it starts to get confusing...
Most applications, bandwidth testing sites, and ISPs will tell you what kind of bandwidth you are getting, or can expect to get, as bits per second (bps) some tell you in Bytes per second (Bps) and still others tell you the results in characters per second (CPS) - make sure you understand the measurement they are using. And if that's not confusing enough, a byte or a character is generally 8-bits, but not always! Sometimes it's 7-bits, 9-bits or even 16-bits. BTW: The networking industry, due to this confusion, uses the term Octet which means exactly 8-bits.
So, to figure out the maximum bandwidth on a T1 you take the number of channels (24) times 65,536 and divide the result by eight (to get octets per second) you get 196,608 Octets Per Second. A lot of people will state this as Kilo Bytes per second, thus you often see the 192KBps (Kilo or 1,024 Bytes per second) figure bandied about.
Keep in mind, this is the pure data rate and there is overhead to send and receive data (like the IP protocol wrapper, etc.), so by the time you are done, your data rate will be around 188KBps.
Now on to the over-subscription deal:
ISP's will generally purchase a T1 from one of the Tier-1 or Internet Backbone providers such as UUNET, Sprint, BBNPLANET, Cable and Wireless (was originally MCI's internet backbone), etc. and connect it into their network - these usually cost over $1,000.00 (Though, I can get a Sprint Internet T1 right now for $930.00).
They often have Dialup users, Web Servers, Database Server, Email Servers, and so forth interconnected to this network, all of which can consume bandwidth.
Then they sell "Internet T1's" to their customers, for a reduced charge - what they are really selling are T1's connected into their network, which then allows access to the backbone providers T1 through their network. They will often sell five to twenty of these "Internet T1's". This can provide them the opportunity to snoop on any traffic that you are sending across their network, they can also block, cache, or perform traffic shaping, which can allow someone else's traffic to go ahead of your traffic, or your ahead of someone else's.
This system usually works out well, as most people don't fully utilize all the bandwidth all the time and most ISP's don't do anything fancy to the traffic, but can cause issues if you don't know what you are getting into.
Questions you should get answered from your ISP:
Who is their Internet provider?
Is their Internet provider a Tier-1 or Backbone provider? (if not be careful)
What does their network look like? Ask for a network diagram.
How much bandwidth do they have?
How many dialup users do they have? How many T1 subscribers do they have?
Ask to see their bandwidth usage reports.
How reliable is their network? Do they have more than one upstream provider?
Do they do BGP4 routing with their upstream providers? (what is their AS number?)
Get a network diagram of their upstream providers.
Do they own their own IP addresses or have they been assigned them by their provider?
How many IP addresses can they give you?
Do they provide DNS servers? Can they setup reverse DNS zones for IP address they assign to you?
Do you do network caching? Filtering? Traffic Shaping?
To sum this all up:
You can send and receive approximately 188k Bytes per second (or 1,504k bits per second) across a T1.
Nothing is simple. The telecom (and networking) industries have many names for the same thing - which can be used to confuse and complicate simple things.
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1) These are available from Brookstone for $150...
2) Delcom Engineering has a "USB Visual Signal Indicator". This includes RED, GREEN, and BLUE LEDs, Piezo buzzer, 2 meter USB cable and USB powered circuit. The cost? $69.00 each... All you need to add is a globe...
If you want to play around with this stuff, Delcom Engineering also makes USB chips, cables, etc. and they make USB development board for $49.00 that you could you could use to build what ever you wish...
First off, some basics: Channel = 65,536 (or 64k) bits of data both ways. T1 = 24 channels. DS3 = 28 T1's. OC3 = 3 DS3's OC12 = 12 DS3's OC192 = 192 DS3's Channels are also known as DS0's. T1's are also known as DS1's. DS3's are also known as T3's. NOTE: In Europe T1's are called E1's and have 30 channels (DS3's are called T3's). With this in mind, a full T1 can transmit 1,572,864 bits per second (or divided by 1,024 you get 1,536kbps) and receive 1,572,864 bits per second at the same time. There are three components to a T1 (or a DS3): A local loop connection to you, a local loop connection to your ISP, and the interconnecting circuit. There are costs for all three parts. BTW: T1's were (and still are) originally used for voice communications, and can have 24 phone conversations going on at the same time. Each conversation basically uses 8,192 8-bit digital samples per second to transmit voice traffic (CD's use 44,000 16-bit samples). What the heck is a Frame-Relay T1? Sometimes an ISP will sell you a Frame-Relay T1 instead of a true or full T1 (FYI: A true T1 has four wires, a frame-relay circuit has two.) Frame-Relay T1's are shared T1's - this basically means that they provide a certain amount of bandwidth and anything above that may or may not make it to the destination depending on how busy their network is at that point in time. This is usually set to 50% of the total bandwidth and is called CIR (Committed Information Rate). After this it starts to get confusing... Most applications, bandwidth testing sites, and ISPs will tell you what kind of bandwidth you are getting, or can expect to get, as bits per second (bps) some tell you in Bytes per second (Bps) and still others tell you the results in characters per second (CPS) - make sure you understand the measurement they are using. And if that's not confusing enough, a byte or a character is generally 8-bits, but not always! Sometimes it's 7-bits, 9-bits or even 16-bits. BTW: The networking industry, due to this confusion, uses the term Octet which means exactly 8-bits. So, to figure out the maximum bandwidth on a T1 you take the number of channels (24) times 65,536 and divide the result by eight (to get octets per second) you get 196,608 Octets Per Second. A lot of people will state this as Kilo Bytes per second, thus you often see the 192KBps (Kilo or 1,024 Bytes per second) figure bandied about. Keep in mind, this is the pure data rate and there is overhead to send and receive data (like the IP protocol wrapper, etc.), so by the time you are done, your data rate will be around 188KBps. Now on to the over-subscription deal: ISP's will generally purchase a T1 from one of the Tier-1 or Internet Backbone providers such as UUNET, Sprint, BBNPLANET, Cable and Wireless (was originally MCI's internet backbone), etc. and connect it into their network - these usually cost over $1,000.00 (Though, I can get a Sprint Internet T1 right now for $930.00). They often have Dialup users, Web Servers, Database Server, Email Servers, and so forth interconnected to this network, all of which can consume bandwidth. Then they sell "Internet T1's" to their customers, for a reduced charge - what they are really selling are T1's connected into their network, which then allows access to the backbone providers T1 through their network. They will often sell five to twenty of these "Internet T1's". This can provide them the opportunity to snoop on any traffic that you are sending across their network, they can also block, cache, or perform traffic shaping, which can allow someone else's traffic to go ahead of your traffic, or your ahead of someone else's. This system usually works out well, as most people don't fully utilize all the bandwidth all the time and most ISP's don't do anything fancy to the traffic, but can cause issues if you don't know what you are getting into. Questions you should get answered from your ISP: Who is their Internet provider? Is their Internet provider a Tier-1 or Backbone provider? (if not be careful) What does their network look like? Ask for a network diagram. How much bandwidth do they have? How many dialup users do they have? How many T1 subscribers do they have? Ask to see their bandwidth usage reports. How reliable is their network? Do they have more than one upstream provider? Do they do BGP4 routing with their upstream providers? (what is their AS number?) Get a network diagram of their upstream providers. Do they own their own IP addresses or have they been assigned them by their provider? How many IP addresses can they give you? Do they provide DNS servers? Can they setup reverse DNS zones for IP address they assign to you? Do you do network caching? Filtering? Traffic Shaping? To sum this all up: You can send and receive approximately 188k Bytes per second (or 1,504k bits per second) across a T1. Nothing is simple. The telecom (and networking) industries have many names for the same thing - which can be used to confuse and complicate simple things.