| What exactly are the differences between Cable | | | | Service Comparison. |
| and DSL Internet services? | | | | One of the advantages of DSL over cable |
| First let's define our terms. | | | | modems is that the line to the exchange or |
| Bandwidth vs. Latency: | | | | "switch" is not shared. Though ISPs trying to sell |
| Bandwidth & Throughput | | | | DSL services will tout this as a major advantage, |
| Digital bandwidth or throughput is a measurement | | | | slow cable modem speeds have very little to do |
| of the amount of data that can be transferred | | | | with this and have much more to do with the |
| over a digital line over a specific amount of time. | | | | fact that cable service is shared among many |
| Latency | | | | users and services. |
| Latency is the time it takes to deliver a packet of | | | | ISPs tend to enforce a bandwidth cap on both |
| data from one place to another. This includes the | | | | DSL and cable modem services. |
| time it takes for an electrical or optical signal to | | | | The first cap is on data transferred per service |
| travel a certain physical distance (propagation | | | | period (usually per month). From my experience, |
| delay) and the time it takes to process these | | | | DSL data transfer caps are more rigidly controlled |
| signals along the way (processing delay). | | | | than cable services. Your data cap may be as |
| So bandwidth is a measure of frequency or a | | | | little as 1 gigabyte per month or, in the case of |
| rate of service delivery while latency is a | | | | most cable modem services, unlimited. |
| measure of time or signal delay. | | | | Both cable and DSL services have a cap on |
| Technology Comparision. | | | | bandwidth. Your service provider may promise |
| Cable service uses signals transmitted through the | | | | you a certain downstream limit and a certain |
| same coax cable that cable television uses. DSL | | | | upstream limit. This means that you will generally |
| uses normal phone lines to send digital signals to a | | | | be able to sustain a certain bit rate while |
| DSL modem. | | | | downloading or receiving data and a different bit |
| Coaxial cable has a far greater capacity than | | | | rate while uploading information. |
| RJ-11 phone cable. But, the coaxial cable coming | | | | In general, because of the far greater capacity of |
| into your home is shared with many people | | | | coaxial cable and the fact that only a certain |
| outside your house and provides many services. | | | | number of lines exist connecting you to your |
| Cable modems have higher bandwidth though the | | | | switch, cable modems, if uncapped would provide |
| connection is shared among cable users in your | | | | advantages in bandwidth over DSL modems. In |
| service area and even with your digital cable box. | | | | the real world, this is not the case. Both DSL and |
| As a result the performance is quite similar to | | | | Cable companies limit bandwidths at both the |
| DSL. | | | | modem level and at the service provider. |
| Generally, cable modems can achieve better peak | | | | Shop Around. |
| throughput, but this high bandwidth is not | | | | If you are shopping around for a service or |
| consistant and depends, again, on load, affected | | | | thinking of changing services, the best advice I |
| by time of day and other factors. | | | | have for you is to ask other users about their |
| DSL service usually provides a more constant, | | | | service. One of the best web sites I've seen for |
| consistant feed, with lower latency. The distance | | | | sharing this data is |
| to your exchange or "switch" is the main factor | | | | This site provides user-submitted reviews of their |
| that determines DSL quality of service. Look for | | | | broadband service and charts day-to-day service |
| the green (in Toronto) phone exchange box in | | | | fluctuations. Speed tests and other tools for |
| your neighbourhood and note how far your home | | | | optimizing your connection are available as well. |
| is from that box. | | | | |