It's quite widespread...take a look at some of the maps for services here (if not in the US, links to other regions are at the bottom of the page):
www.downdetector.com/companies
Typically it is an issue amongst the ISP's in play getting us from our localized networks over to SE's ISP. Usually, it's either the third party peering partner's network acting up (like Level3, Verizon's UUnet/Alter.net, Telia, etc.), or it is an issue occurring at the exchange points on either end of their network.
That is why your sessions to other servers may be running just fine. The problem isn't within your local network, but one of the networks along the specific path your ISP has assigned you to get to SE's ISP. Just like you don't take the same highways to go from LA to Atlanta as you would to go from LA to Seattle---you take different routes to get to different ISP's in other regions. The routing is determined by your ISP's policies, and will require their Tier3 team to get involved with investigating and addressing it. Not the guys typically answering the 800 number or the guys that come check your lines (tiers 1 and 2)--you need the Tier3 (Engineers) that work on things deeper into the network. You my do better to contact them through online methods if available--the phone centers are often limited in what they can say and do for you.
You may see some bad spiking at some of these hops in between you and the addresses starting with 199, 124, or 195 if you run a tracert to your lobby server. Here are the registered names for some of them them:
neolobby02.ffxiv.com (Aether - 199.91.189.74)
neolobby04.ffxiv.com (Primal - 199.91.189.93)
neolobby06.ffxiv.com (Chaos - 195.82.50.9)
(never had reason to match up the Japan lobbies, but they use the same name scheme with odd numbers 01, 03, 05--and their IP's start with 124)
Such traces can be an invaluable tool for that same Tier3 department--it gives them a roadmap of the particular route you take, and gives them indications of where they need to be investigating.