Well ..... not really.
THE NON-OBVIOUS ANSWER T1 OVER DSL: PCI Compliance
If you have a retail business that has to comply with PCI Compliance and Retail Data Security......be careful. Ignoring the PCI Compliance standard is risky. Retailers can be fined and even lose card processing privileges.
Network Security Compliance is Mandatory for Retailers, Banks, and other Financial Institutions .... and any companies saving or transmitting personal data over the internet. Identity theft is the main driver behind this compliance. So when you are networking with DSL, often the cheap routers, access devices, firewalls, VPN appliances, and Wireless LAN's that come bundled with them will fail a PCI Audit. But there are some exceptions.
THE OBVIOUS ANSWER:
You ask "When would you choose a T1 over DSL?"
Bandwidth is transmission capacity. But when your needs for a more robust, dedicated circuit with an SLA OUTWEIGH the additional costs, then you pick a T1.
DSL Pros: Inexpensive, most bandwidth for the buck.
DSL Cons: Weaker SLAs, Slow Mean Time To Repair, Aggregated service.
T1 Pros: Dedicated 1.544Mbps, Good SLA, Most problems fixed remotely.
T1 Cons: More expensive to to the cost of the local loop to the central office.
The transponders used for transmitting the signals are placed at a distance of 22,300 miles above the equator. The time required for a signal to cover the two-way distance is approximately 480 milliseconds and it is known as latency time. There is another latency time between the network operations center and the World Wide Web. These two time factors add to a total latency time of around 600 milliseconds from the time the signal emits from the dish to the time it is received back at the dish. This is known as the ping time. The ping time causes delay hence, Satellite Internet is not considered suitable for many real-time applications. We shall see some of the drawbacks that are caused by ping time delays.
As a home user if you want to play online games Satellite Internet may not be the ideal option. Setting-up virtual private networks (VPN) through Satellite Internet is not a viable proposition. There are many new technologies being developed to overcome the delay in ping times. One such technology is RELIA technology which has pending US patents. This technology overcomes long ping times and packet loss, improving the performance and reliability of Satellite Internet services. The technology has been developed by Niwot Networks. Apart from ping time delays there are factors such as packet loss which hamper the quality of Satellite Internet communication. RELIA helps in reducing ping time and packet delays that happen if data and voice packets are transmitted over naked TCP.
There is reason for Satellite Internet users to be glad. The tests carried out with this new technology prove that RELIA will definitely help Satellite Internet providers in reducing ping time. In one particular test carried out with 10 files of 1 Mb, losing 8 packets out of 200 with 600 milliseconds ping time, the naked TCP connections failed 72 out of 133 trials before all the files were transferred which is 63%. When RELIA technology was used the failure time was only 7%. It would not be surprising to see that leading Satellite Internet providers such as HughesNet using this technology over naked TCP to reduce ping times.
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