Why are ISP's installing routers on my site when the feed is a form of ethernet already?

Solution 1:

This is typical for enterprise-class internet connections provided by telcos. You manage your equipment, they manage their equipment (located at your site), and a clear demarcation point is provided at the router port that the telco provides for you to connect your equipment.

Do they really need a $2000 router at every customer site? Probably not. What it boils down to is that they are using equipment that is known and respected: using devices that are unlikely to fail supports compliance with their SLA, so they choose equipment that is well-known, dependable, and interoperable.

As cable companies and other lower-cost providers continue to expand into business-class data services, it is entirely possible that traditional telco ISPs' on-premise equipment will start to get leaner in order to support more competitive pricing.

I have seen plenty of offices that have a ~$100 DOCSIS 3.0 cable modem providing a 50 Mbps primary connection, alongside $1,000+ Cisco equipment serving as the demarcation point for a 1.5 Mbps T1 or MPLS connection from a telco. Of course, the slow telco connection is costing the business at least twice as much as the fast cable connection. Sure, the telco provides a better SLA, and the cable connection usually has slightly more latency and jitter, but you can guess which one is the primary WAN connection on the firewall... and you can guess which one the business would prefer to keep if the budget axe were to fall.

Solution 2:

This is just normal practice...

Example:

I have two connections at our home office.

One cable (60/20) and one isdn (20/1)

The isdn ISP delivers one box that is everything in one: router, wlan and modem.

The cable ISP delivers two boxes: a router and a modem.

Both of these connections go into our office and connect to my zyxel router.

I've talked to both of these ISP's for a while to understand what's going on.

If you read their contracts, it mostly says that they will offer free service if the connection fails. Reading a bith closer it actually means that they will fix it.... up to the point of their equipment, from there on you're on your own.

A second reason is for them to do offsite maintenance. While it just looks like a router these things are often also used for keeping statistics. This way if you say there is a problem they'll simply login to their equipment and magically fix it.

And another reason would be that if you were so stupid to directly plugin a computer, the computer wouldn't get an external IP and be open to the net.

But in the end, it never slows down your eventual connection, it will only make it faster and more reliable. and don't think it will limit your possibilities. With every setup I have encountered (even the all in one box) you can still grab the external IP and use every single damn port.

Solution 3:

Besides all the above entries;

If there is a junction of suppliers, then the responsibility border of each supplier must be clear and definite and I suppose the mentioned ISP does that by using a separate router.

Especially active units are very critical; as a minor change of one supplier or an inhouse technician servicing a shared unit may cause a major problem to a system which is in the responsibility area of another supplier.

It eventually costs to all sides including the customer in terms of time and money.