With your current setup, you will basically need to disconnect the cable that plugs into your legacy Home Phone modem (which probably leads to an RJ31X jack where your alarm system connects) and connect that cable to the TEL 1 jack on the back of the Ignite gateway. That's going to be very difficult to do with the Ignite gateway located on the upper floor. The basement is the logical place to install the Ignite gateway but now you have to worry about how to provide good network and Wi-Fi connectivity to the rest of your home.
The level of difficulty is increased yes, but possibly still can be done, however do not expect the typical rogers ignite installer to do this or know how to do this for you, its not his or her fault , don't blame them for not knowing or being able to do it, its out of scope for them. A specialized cable technician or alarm technician may know how to do this or someone like myself who has years and years of telecom experience.
Most homes have multiple wires to each phone jack, however we typically only use a pair of these wires (2 conductors) if you just have one phone line in your house the rest of these wires are unused and there if you need to have a second number or a fax line or a VDSL/dry loop pair.
In most cases, if they're not being used and there is sufficient number of free pairs available, A knowledgeable alarm technician or cable technician or yourself Can fix this if the Ignite Gateway device has been installed upstairs in a bedroom or office where an unused telephone jack exists, wire up the telephone jack a certain way using the secondary pair (orange/white or bumble bee) so that the home phone signal is sent out of the modem, into the wall jack, goes on the secondary pair all the way downstairs into your basement, then gets cross connected into your Alarm System RJ31X jack to seize the phone line if the alarm were to go off, then the phone line would come out of the RJ31x jack and get punched down onto the primary pair of your punch down block where all your phone jacks in your house terminate onto, this will then back feed the dial tone to all your jacks which are programmed to the first pair (blue/white or Christmas tree)
I have said this earlier, if you are not knowledgeable or unsure what to do or afraid to try this, leave it to a professional technician. Just to note, if you want to plug a phone in the same room as your ignite gateway do NOT use a phone splitter, because if you accidentally leave the phone off the hook it will prevent the alarm from taking over the phone line, your best bet would be to buy a 2 port phone jack for the office or bed room and wire the phone set into the blue/white or Christmas tree pair or even better, if u have a cordless phone connected elsewhere in the house leave it where it is and bring the handset to the office or bedroom.
here is my 2 cents, well rounded up to 5 cents since pennies do not exist
It is a lot of work and lot of labour to wire up something like this correctly and a lot of people will be hesitant to do this plus people will feel uncomfortable when someone tinkers with wires or their alarm system.
Because of that a lot of people have decided not to use alarm monitoring over a phone connection because its quite archaic and grandfathered technology and the traditional phone line as we knew it from bell is becoming less popular.
Some people have even gone as far as talking to their alarm company to see if more modern monitoring methods exist such as using your lan/wifi connection or a 4G cellular wireless connection.
You may not know this but most classic alarms can be upgraded to support these types of connections
I need time to more fully explore this option. Running ethernet lines inside my older house to the second floor isn't an option.
Some folks also use MoCA adapters to bring Ethernet connections to other parts of their home over coax rather than running Ethernet lines.
The main points that I was trying to make is that the installation is doable but you may need to think "out of the box" a bit and and/or make some changes to your current setup, and that overcoming some of these installation challenges won't necessarily be any easier if you switch from Rogers to a different provider.
Also, service providers love "all in one" modem/gateways but wow, they can sure make some installations really, REALLY challenging.
I would just like to add and echo one of the options mentioned about alarm monitoring. I have an alarm and switched to wireless (cell) monitoring thru my alarm company a couple of years ago (well before I switched from legacy digital to Ignite). My alarm company only charged me $5 more per month and it's been FAR more reliable than when my alarm was connected to my wired Rogers home phone. The only time that my alarm has shown "trouble" on the keypad panels due to monitoring being down was when Rogers had that massive cellular outage back in April (because my alarm company uses the Rogers cell network for monitoring). From my experience, cell networks these days are more reliable than residential wireline networks. They have extremely robust battery backups in their cell tower base stations. And as was mentioned by someone else, Rogers has been removing battery backups from their coax/fibre neighbourhood nodes for their residential services, so chances are your home phone will not work during a power outage.
When my alarm was connected to my old wired Rogers home phone service, my keypad panels displayed "trouble" many times (over the course of several years) due to the home phone service / cable going down multiple times. So I would highly recommend switching to cell monitoring if your alarm company doesn't charge too much more for it as I find it extremely stable and reliable...but it's an additional cost that you have to factor into your decision about switching to Ignite. Most alarm companies these days only charge a few dollars more per month for this feature, and some companies don't charge anything extra at all.