My ADSL Max connection was rock solid for many years with a download speed of just over 6 Mbps, an upload speed of just under under 0.4 Mbps and a latency of around 40 ms.
Some time ago, our local exchange was upgraded from 20CN to 21CN so ADSL 2+ became available for the first time.
I eventually asked my ISP if I could be upgraded from ADSL Max to ADSL 2+ which they agreed to arrange at no cost to me.
I was assured that I would not need to change anything in my existing modem/router and that my static IP address would remain the same. As expected, speeds were a little variable for a few days after the upgrade took place but things settled down and my download speed is now just over 16 Mbps, my upload speed is just over 1.0 Mbps and my latency is around 20 ms, all of which are quite sufficient for my modest needs.
However, I am now contemplating a change of ISP but am concerned as to whether this could compromise my present speeds and stability of connection.
My question is what would actually be changed? Presumably the physical connection to my PCP and back to the exchange would not need to be touched but would there be any physical changes made within the exchange itself - a different ADSL 2+ line card for example? Note that there is no LLU at my exchange.
What other factors could affect the quality of my present connection if I choose to migrate?