 Hey, guys, welcome back to my YouTube channel. This is Daniel Roestel here. I want to do a video today regarding the cool feature on the Synology NAS known as Quick Connect, and just doing a little bit of looking into how exactly this works. Synology NASs are fantastic tools, really, really useful if you particularly are doing videography work and you are generating gigabytes of data every day, every week, and you need somewhere to store that stuff. The first thing I typically do when I finish a video, even one of these little sort of webcasts for YouTube, is I want to back up that video file and then put it somewhere on the network or out of my local environment. Now, for proper backup, you want to do one, typically on-site backup and one off-site backup, so you can put it on your NAS, but you also then need to go ahead ideally and get that over to the cloud or someone else's computer, for that matter. It just needs to be geographically separated from your home network environment. Now, typically when I would be traveling and making videos, which I've only been doing for the last couple of years, but I would bring along a external SSD, and if I finish the video project, I'd put that on my SSD, and then when I got back home, I would get that SSD, external SSD, a Seagate, whatever, and I would put that onto my NAS and then delete the files on the external SSD and rinse and repeat, and that's probably what most people do, in fact, but there is an actually simpler way if you already own a Synology NAS. Buried a little bit into the menu of the Synology NAS under Advanced Settings, External Access, you'll see a little thing called External Access, and what this is is Quick Connect. Quick Connect is a way to access your Synology NAS from outside of your local network, right? Typically, when you're connecting to your Synology, you're on your LAN, and it's all wired up over ethernet cable, and it's very easy to do. What happens when you are beyond the local network? So those of us who have done such cool and geeky things is running our own web servers from our homes, or I believe my first job was running a CRM from an old laptop in the office at one point. You know that in order to get local infrastructure accessible from outside of a home network or an office network, you typically need to set a port forwarding on the router in order to allow that port to be connectable from outside the network, outside the LAN on the WAN, the wide area network. Now, if you don't do that, there are some workarounds that I've seen over the years, and they typically require something called Proxying or some sort of Proxying system. So I used the Quick Connect recently in the US, and I was amazed and delighted with how well it worked. I would finish a video, and I could log in via Synology Quick Connect, and I could upload to my NAS just as if I was in my house. Now, the thing that made me a bit suspicious of how it worked, or I suspected it was a proxy server, was because of the speeds, it was a slower process. So I suspected that when I was uploading to my NAS via Quick Connect, there was a proxy server. Between, in other words, I was actually uploading from, let's say, a hotel room to the proxy server. Then the proxy server was passing that file on to my NAS, and if I wanted to grab something off my NAS, the reverse process, upload from my local environment, sorry, upload from my NAS to the proxy server, from the proxy server, download to where I actually wanted to access the file. So that was my suspicion, but I couldn't be sure. So I plugged into Google how Quick Connect works, and I came across this interesting resource. This is the official, now there's articles, and I didn't want to just kind of plagiarize someone else's writing, so instead I decided to plagiarize Synology, right, that's legit. So Synology have a whitepaper, and more seriously, I went for this resource because it's actually authored by the manufacturer. Now the cool thing was about Quick Connect, you don't need a, you don't need port forwarding, it really, really works out of the box. So how does this work exactly? So this whitepaper spells it out basically, and they get to the juicy part right about here. Quick Connect hole punching. I'm gonna read you the lovely words of the Synology documentation here. If no direct connection can be established, right, so if you don't have port forwarding set up on your network, therefore there's no way to directly connect from your NAS box at home to your hotel room in Rome or Bodega or Seattle, Washington. If no direct connection can be established, the client will attempt to establish a virtual tunnel between the client and the NAS via Quick Connect to allow a temporary direct link for data transmission. This technology allows the server and the client to experience internet synchronization performance very similar to connection via one IP slash DDNS without physically having such an environment. Hole punching works by initiating a virtual tunnel from the client to the NES with the aid of the Quick Connect server. Sounds very much like a proxy server. So here's how it works. One, the NAS sends out a request to the Quick Connect server and keeps the hole, a random external port punched by the request on the NAT in front of the NAS open to receive a hole punching request. Similarly, the client sends out a request to the Quick Connect server to create another hole on the NAT in front of the client. So both sides are using hole punching. You, let's stop talking about client servers. You trying to access your NES and the NES in your network. Two hole punchings going, hole punchings going on. Three, the Quick Connect server will deliver the whole information of the NES to the client and vice versa. So you tell each other how to get into one another's networks. The NES will try to establish a connection to the client through the punched hole on the client side. Once the client receives the hole punching request from the NAS, a hole punching response is sent back to the NAS via the punched hole on the NAS side. And we have a nice little diagram to make this easy. So there is indeed a Quick Connect server. There's not really a punching server. It's actually more passing on workarounds to the local network environments on both sides. Hole punching handshake, virtual tunnel. And that is the figure one here, Quick Connect hole punching mechanism. Once the virtual tunnel, I'm gonna put myself a little bit smaller here. Once the virtual tunnel is successfully established, remote client can use this connection to communicate with the NAS directly and no network relay is needed. In case where the virtual tunnel cannot be created, a relay service is available for data transmission when traffic is relayed. It goes through a Synology relay server before arriving at its destination, requiring more time compared to direct connections or Quick Connect hole punching. So I'm gonna read that again. Requiring more time compared to direct connections or Quick Connect hole punching. So this is a slower data transmission process. The Quick Connect relay service serves as the final option for data to be communicated between the NAS and the client. So they've got kind of various ways to do it. Now, I believe you can probably set up direct connectivity by configuring that port forwarding. I haven't gotten around to doing it yet, but I like the fact that they've given you all kinds of options. If the hole punching fails to create a connection, the client will make one last connection attempt by creating a virtual network tunnel using the Quick Connect relay service, which works as follows. To initiate the relay service, a client will send a request. They go into the detail again about how the relay server works. It's kind of what you'd expect. It can cause a significantly in-dated delivery and thus the last method a client will take in attempting to reach the server. And figure two shows that relay service working in the middle here. I suspect that might have been what I was using when I was accessing the NAS from outside of my network. And there is more details here that we're not gonna get into. So that is basically how this thing works. In other words, there is a preferential method. There is a hole punching mechanism. And if needed, direct connection is possible and the hole punching mechanism doesn't work, it'll transmit data through a relay server. Now I get that that is super complex. As a non-IT professional, just as a guy who likes all this geekery and hence it's a big focus on my YouTube channel, I get the concepts there, even if the precise details to drill down into exactly how a hole punching handshake is established is knowledge for people on a different paid grade than I am on. So I hope this video has been useful. If you are a Synology user, you've been impressed by Quick Connect and you wondered how it worked, here were the tech details. Thank you guys for watching. And if you would like to get more videos from me, please feel free to subscribe to this YouTube channel and of course, have a great day.