I don’t know if I understand the question, but I will give it a shot.

1. Most dialups at some point connect via IP and thus can be managed like any other IP enabled device.
Depending on the device, all computers that use dial up networking will always use TCP/IP. The way that it works is the host calls the server the server responds with issuing an IP address. This handshake is the same no matter the protocols that may be used.


2. Modem dialups are on the decline.

This is true
But
There are many areas of the county that still do not have DSL and there are even more that cannot even get DOCSYS Cable Internet, satellite is an option, but a very expensive and non reliable.
Dialup Modems are used for other devices that will be used for many more years to come.
Fax machines use dialup modems on standard telephone lines, the reason that they are still are around is for document transmission. It is easier and takes less time to sign a paper and fax it then to mail. Why not use email you ask? Well email is not secure and information can be intercepted or even falsified by unknown parties, and you really cannot sign the document then email it.
Credit Card Terminals. A lot of smaller companies still use dial up credit transactions, it’s cheaper because they do not have to pay for a broadband connection.
Backup systems and remote connections. In some cases I have seen dialup used for a backup connection when a server is down or your T1 or other Telco connection is down you can still dial up and connect to the network
Remote connection to a server to run commands is more secure than having accounts accessible over the internet, when you dial in you are connected directly to the network.

So dialup is not going away anytime soon but is slowly losing popularity as a main connection to the internet

Hope this answered your question

2. modem dailups are on the decline.

D. Shired, CTM