Helping people with computers... one answer at a time.
Upgrading equipment is a common way to get better performance or increased capacity. Upgrading a DSL modem, in and of itself, will likely do neither.
We always hear people talking about upgrades/updates for RAM, programs, BIOS, etc., but what about DSL modems? Do they ever need upgrades? How long does a modem typically last? Do they give any warning signs when they're about to fail? What does a $75.00 modem do that a $40.00 modem won't? What should one look for when buying a first modem or replacing one that has failed? If an ISP provides a modem as part of the install package, is that modem ISP specific or can any modem be used?
Lots of questions about a topic that we rarely think about. But it is kind of interesting. Does it ever make sense to replace or upgrade a DSL modem?
In my experience the answer is a fairly clear "no". The modem is one of those pieces of equipment where "if it ain't broke, don't fix it" clearly applies.
A upgraded DSL modem won't impact your throughput - that's set by your ISP. No matter how fast or snazzy a new modem might be, it's still only going to transfer data as fast as your line is configured for.
The only time you'll want an upgrade or replacement is if your modem fails, or if ISP says you do. That may happen if the ISP changes characteristics of your line, including, perhaps, the speed or underlying technology.
A DSL modem is like any other piece of networking equipment - if operated in a proper environment (well ventilated with no temperature extremes, and kept free of dust), it should easily last years. But also like any other piece of hardware, stuff happens. My own DSL modem suffered a catastrophic failure and stopped working completely one day. (I'd suspect this is the most failure common scenario - it just stops working.) Why did it fail? It's hard to say - it could have been as simple as a power surge or perhaps a manufacturing defect that finally gave in.
All DSL modems are most definitely not created equal. Make sure to check with your ISP for specific modem brands and models that will be compatible with your DSL. In my case, for various reasons, my telephone company has me on a fairly old type of technology called "Frame Relay". (More current technology is called "ATM"). The upshot was that when I went looking for a replacement modem, new models were not available. My only option was to find an exact match for my modem on eBay. Dirt cheap, but still somewhat time consuming to come by. (I've since purchased a second as backup.)
My case was simple - I was able to simply drop in the replacement modem, but not all situations are that easy. Depending on how your ISP has configured your line, your DSL modem may need to support login and authentication protocols - in other words your modem might need your account name and password in order to connect. In addition to Frame Relay versus ATM, there are other characteristics of DSL lines that are controlled by your ISP and the telephone company providing the physical connection.
Similarly, some DSL modems also act as NAT routers. That can get confusing if you then install a second NAT router behind your modem - some types of internet protocols do not work well across what's called "double NATting". When replacing a modem you'll need to make sure that you have the same features and functionality as the old one. Again, this is an area where you should get guidance from your ISP.
And that, perhaps, is the real bottom line here. While you are probably not required to get your modem from your ISP, you'll certainly want to talk to them about compatibility. Most will provide you with a list of specific modems that should work for you, and will tell you whether additional configuration is required once the new modem arrives.