The Internet. It provides much higher bandwidth and reliability that, well, it has any right to given how complex it is and how many individual 'selfish' interests drive it. But, the last frontier is latency. Consistent and low latency to be exact.
Consistent latency (jitter) is a function of congestion, how many other packets are vying for the output queue.
Low latency is a function of the number of routing hops and the speed of light. Quantum entanglement might be our future, but optical to electrical serialisation and deserialisation is our now.
So my commute this am. 5 minutes on the bike. but then an eternity on the 'information superhighway'. See the chart. The 'best' case scenario is ~11ms to a local datacentre. The worst case? ~10seconds. Yes you see that properly. Some packet more or less literally walked across town to achieve that goal.
Now, is a 10s packet worth it? Many claim that 'every packet is sacred'. They are wrong. Drop early, drop often. Congestion management on TCP protocols is (usually) done via packet loss. It makes no sense to keep holding data longer and longer. New congestion control algorithms (e.g. codel) are better. But we face a mix of them, which is actually quite hard to model. Lookup 'buffer bloat'.
Packets Pings Host Loss% Snt Last Avg Best Wrst StDev 1. 10.173.213.254 12.2% 74 7141. 1211. 1.0 9146. 2269. 2. XXX.XX.125.25 10.8% 74 6998. 1382. 1.4 9953. 2468. 3. XXX.XX.125.45 11.0% 73 7859. 1383. 6.7 9810. 2496. 4. 10.180.130.157 11.0% 73 7715. 1424. 6.3 9716. 2510. 5. 10.180.129.18 13.7% 73 8576. 1079. 6.9 9578. 2078. 6. XX.XXX.214.59 13.7% 73 8432. 1056. 10.7 9435. 2022. 7. XXX.XX.XX.XXX 13.7% 73 9292. 946.8 10.5 9292. 1750.
Now, what can one do about this? Not much it turns out. You could use some dual-technology channel-bonding sd-wan magic, and hope their cloud that stitches it together is immune. You can move those servers back to your local network. You can drive to the cloud provider(s) and ask nicely to sit in their lobby and work. Or maybe whip out the rolodex and start dialing the rotary phone.