Forgive me as I have very little domain knowledge in this area, I'm helping out at my parent's office and was asked to look into speeding up the internet. They've been using this IT guy that I think is ripping them off… They have a T1 line which costs a ton and only provides 3 Up, 3 Down. The IT guy is convinced that it is necessary for the VPN which is used by employees to access documents on the office server when they're out of the office. They also use it to access some applications which run on the server.
I understand that this is for reliability but if you don't have a T1 line going to your house, how are you going to see that reliability? Am I missing something about VPNs? Is the T1 necessary at all? I'd think you need T1's from point to point? Why can't we just put a VPN on a normal cable connection?
I'm just about to finish my CS degree, but know very little about networking, so be gentle please.
Best Answer
First of all, T1 gives you around 1.5Mbit/s in both directions, not 3Mbit/s. If you're seeing 3Mbit/s, it may be bundled from two separate lines.
Now, for VPN, if that's IP-based VPN as 99% of VPNs currently are, of course it doesn't matter if your physical interface is T1, E1, ATM OC-3 or 10GE WAN PHY - it's just used to provide higher-layer connectivity - which for VPNs (IPsec, DTLS or whatever) is usually IP connectivity. As soon as you obtain IP connectivity, you should be able to establish VPN sessions.
From the description you provide, that T1 line (or bundled T1 line) is used as a hub for employee remote connectivity. This may mean, that the VPN device has T1 ports built-in and that's why the "IT guy" claims T1 is needed to provide the connectivity, or there are some other constraints.
Given the costs of dedicated circuits, I'd rather ask local available ISPs about Ethernet line - be it 10Mbit/s, 100Mbit/s or sub-rate 1GE/full-rate 1GE. You'll get more for less (propably), and still get IP connectivity which is needed for VPN sessions.