VPN

As you probably imagined, there is a fairly easy solution to this problem as well, known as VPN (virtual private network). Many of us use temporary VPN connections from home to get network access as necessary; but you can set up what amounts to a permanent connection from a remote site, to your HQ network, by way of the public Internet by use of VPN as well. One possible solution (out of many) is to use a Cisco SR-520T1 router at your HQ (in the case that you had a T1 connection from your ISP) and at the remote end, a Cisco RVL200. Just one other possible solution would be the use of two Netgear FVS318s -- one would be located at your HQ, and the other at your remote site.

Finally, let your imagination run wild and think about some of the extra functionality you can enjoy after getting a good network connection at your remote site. Probably the most obvious one is e-mail. Not just the text now, mind you: Quickly download all the links people send you. Download a PDF of a piece of equipment at the site. Put an extension of your VoIP phone system at the transmitter site. Install IP/video cameras looking at the front door or gate. Locate any number of backup servers at the transmitter site. Allow yourself remote access to any and all embedded Web servers that live in so many pieces of equipment we use. Start using SNMP (Simple Network Monitoring Protocol) remote controls. Use NTP (Network Time Protocol) to synchronize all the various time references that live at the site, so when you go back and look at error logs, all the times match up. Maybe even an audio stream for a backup STL.

Little stuff like that.

It's about time broadcasters started catching up with the rest of the communications world in the way we use networks and the Internet. The possibilities seem just about endless.

Terms

LAN: local area network

WAN: wide area network

LAN bridge: A device that makes a physical connection between two networks that are of the same subnet. One end of the bridge is connected (typically by Ethernet) on one network (at the headquarters for example) and the other end at a different location remote from HQ. As the LAN bridge receives Ethernet frames on its network interface, it writes the source and destination MAC addresses into its MAC address table. In this way it learns where hosts are located; and when hosts on one end need to reach the other end of the bridge, it passes those packets through. It does not pass packets that don't need to reach the other end.

VPN: virtual private network. There are two important aspects of network security dealt with by way of VPN. The first is authentication: A router at the HQ will be able to authenticate a remote source of packets as being one that is legitimate. This prevents unauthorized users from accessing a private network. The second is encryption. By encrypting the payload data in the packets sent between two ends of a VPN connection, no one in between will be able to read them. So, in using both authentication and encryption, it's possible to use the public Internet for private network connectivity.

Resource Guide