Name of your Internet Service Provider (ISP): Comcast
Ticket or reference number from your ISP: Contacting customer service is pointless because YouTube.com works just fine. Square-Enix needs to work directly with Comcast or we will never see resolution of this issue.
State/Country: Washington, USA
Date/Time (When did the issue start happening, at what specific times does this issue arise, if any.): Been going on for the last couple of months
Frequency (How often does the issue occur?) sporadically, albeit, occurring late at night (12AM PST - 2AM PST). Lagging out has become consistent and actually occurred during the day today (like around 10AM PST and now at 9PM PST). I've lagged out twice today. Interestingly enough, one of my FC mates in West Virginia also lagged out at the same time that i did.

Content (Which content were you playing in-game when the issue occurred?): Grouping up (ironically, as either a PLD or WHM). Also seen this happen on the landscape.

Which in-game World were you playing on when the issue occurred? Cactaur
Traceroute records (optional) (Learn how to generate traceroute record)

PS C:\WINDOWS\system32> tracert 199.91.189.145

Tracing route to 199.91.189.145 over a maximum of 30 hops

1 12 ms 10 ms 10 ms 96.120.100.217
2 * 10 ms 11 ms te-0-1-0-5-sur03.bellevue.wa.seattle.comcast.net [68.86.113.205]
3 11 ms 13 ms 13 ms be-40-ar01.seattle.wa.seattle.comcast.net [69.139.164.6]
4 12 ms 13 ms 12 ms 4.68.71.73
5 274 ms 206 ms 207 ms ae-10-10.car2.Montreal2.Level3.net [4.69.153.86]
6 137 ms 224 ms 108 ms ae-10-10.car2.Montreal2.Level3.net [4.69.153.86]
7 83 ms * 83 ms ORMUCO-COMM.car2.Montreal2.Level3.net [4.59.178.74]
8 93 ms 79 ms 81 ms 192.34.76.10
9 79 ms * 80 ms 199.91.189.242
10 80 ms 80 ms 80 ms 199.91.189.145

Trace complete.
PS C:\WINDOWS\system32> tracert -4 199.91.189.145

Tracing route to 199.91.189.145 over a maximum of 30 hops

1 11 ms 10 ms 10 ms 96.120.100.217
2 11 ms 10 ms 10 ms te-0-1-0-5-sur03.bellevue.wa.seattle.comcast.net [68.86.113.205]
3 12 ms 13 ms * be-40-ar01.seattle.wa.seattle.comcast.net [69.139.164.6]
4 11 ms 11 ms 11 ms 4.68.71.73
5 82 ms 81 ms 85 ms ae-10-10.car2.Montreal2.Level3.net [4.69.153.86]
6 83 ms 82 ms 82 ms ae-10-10.car2.Montreal2.Level3.net [4.69.153.86]
7 84 ms 83 ms 87 ms ORMUCO-COMM.car2.Montreal2.Level3.net [4.59.178.74]
8 80 ms 90 ms 124 ms 192.34.76.10
9 80 ms 80 ms 81 ms 199.91.189.242
10 80 ms * 80 ms 199.91.189.145

Trace complete.
==================
Having ran wireshirk in the other monitor, I'm seeing a lot of the following when I start having issues:

57096 1712.959896 199.91.189.145 <my IP addy> TCP 146 [TCP Retransmission] 55022 → 51990 [PSH, ACK] Seq=2377622 Ack=291201 Win=152064 Len=92
57097 1712.959961 <my IP addy> 199.91.189.145 TCP 66 [TCP Dup ACK 57084#1] 51990 → 55022 [ACK] Seq=291201 Ack=2377714 Win=65024 Len=0 SLE=2377622 SRE=2377714