I wondering if it was at all possible to connect two sites via external modems? Each site would have a external modem attached to aux port of border router. How would routing work in a situation where site A needs to send site B some traffic, no isp involved in this scenario.
This was done often in the past as a backup to leased lines. You can still find it in some situations. Things moved away from this to ISDN and DSL as backup technologies.
Routing works like it always does. Your router at site A examines the destination address, looks in its routing table to determine the interface and sends traffic to that interface. At the other end, the router receives the date, examines header, sends traffic to some interface .... Your router reserves the right to send traffic to the big (null) bucket in cyberspace :-)
Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.