trying to understand this

[carbonbasedlifeform 179]

Microsoft must know 90% of people who play games (or sims) use WiFi, so it should be fine. I wonder if some people think the entire game is going to be streamed online. The scenery will download in the background. The rest of the sim is going to be processed on your computer.

[ChaoticBeauty 6,692]

The simulator will probably already have a large area pre-loaded in advance and maintain a good enough amount of cache in the system that I seriously doubt there is going to be any issue with latency. Even in 3D shooters, latency is not an issue except for those who play competitively or professionally, where the pacing is really fast and extremely accurate aiming is required.

At worst, extremely high latency would cause some pop-ins in an area far from your aircraft. Maintaining enough bandwidth to keep the scenery stream constant is the matter.

[decker89 110]

2 hours ago, n4gix said:

This are the results from my main desktop development computer plugged into my D-Link Router via CAT6 cable:

I don't have a screenshot of my main FS test computer, but the results are less stellar:

Ping = 24 ms  Download = 75.12 Mbps  Upload = 4.92 Mbps

Even though it too is connected via CAT6 cable, My auxiliary router in my Library room is limited to 100 Mbps. I'll need to replace it with a higher spec router to regain performance.

What do you mean by auxiliary router and how is it connected to your main router?

[bosflo 53]

thanks everyone.

 

[simbol 5,820]

3 hours ago, MattNischan said:

This is not a streaming video game platform like Stadia, Playstation Now, or OnLive (RIP) where you need dedicated low latency in order to provide accurate per-frame rendering and control inputs because the game is rendered and processed server side. Scenery data will be streamed to the client as the client enters scenery zones; the game is rendered locally. There's no other way to do it, and that much is super clear because of the fact that you can pre-download and cache scenery areas. Thus, the little extra latency of WiFi is not going to be a problem. Even the slight RTT hit is not going to cut your bandwidth down 80-90%.

I stand by my analysis. If you can stream Netflix, you'll be fine here. When the game comes out, if I'm wrong about that, I'll gladly be the first to eat my words.

You need to get your maths rights:

Wired Connection = 1ms:

10.22 MB/sec = 85.73 mbps.

Now a wireless connection with 20ms RTT, which is just only 19ms more in delay than a wired protocl:

2.54 MB/sec = 21.47 mbps

From 1ms to 20ms it means a 75% performance drop. TCP/IP is massively affected by Round Trip Time. It is a flaw of this protocol.

You can find lots of information about why TCP/IP suffer from these issues here: https://wiki.geant.org/display/public/EK/Welcome+to+the+eduPERT+Knowledge+Base, there are things you can use to reduce it like Windows Scaling, Traffic Shaping, etc. but bottom line nothing beats a wired connection.

3 hours ago, irrics said:

This seems like a generic tech help topic and not really something that belongs in the MSFS area specifically   

I agree, but it seems some users are trying to understand the differences between wired and wireless. I hate to see people discrediting information posted by other users without having relevant data.

Maths don't lie, the entire world of mathematicians have been trying to invent a new network protocol to replace TCP/IP in order to increase the performance of our networks, TCP/IP was invented back in 1970s by 2 incredible DARPA scientists, the protocol is fantastic but it was never designed to withstand high speed throughput over long distances, the purpose of the protocol was to deliver the information in a reliable way. To put things on perspective the first network was a Local Area Network (LAN) and supported only 2.94 Mbps.

In case you are curios, big ISP providers do not run their networks using TCP/IP. They use SONET (Synchronous Optical Networking) and other advanced protocols as a higher encapsulation layer in order to overcome all the limitations TCP/IP have. Unfortunately SONET and such protocols can only be used by very specialized equipment and not  by our home devices.

Big corporations implement traffic shaping using MPLS channels between two distant sites, with this technique they can increase the default TCP Windows Scaling Factor after leaving their LANs for a much larger value, this allows them to alter the mathematical equation for TCP/IP throughput and in turn they obtain much better performance between their sites despite of how far they are. So yes there are solutions for these issues but they are not easy to implement or cheap.

Regards,
Simbol

Edited October 14, 2019 by simbol

[carbonbasedlifeform 179]

1 hour ago, Rob_Ainscough said:

I've already seen in some of the videos where scenery caching wasn't keeping up ... pending how fast one flies and what kind of maneuvers they fly latency will be important as the cache will soon be exhausted.

It's not the same as Netflix, there is additional rendering happen server side per Asobo developers information provided via interviews.  It's not the same as streaming a movie ... clarity of textures will vary based on latency and bandwidth.

Azure is not receiving input and sending output frame by frame. It's being used to create a 3D world based on satellite imagery and various data. That data is downloaded just like anything else, including Netflix. What Asobo is excited about is using Azure's power to create the world, not to send you it's calculations in real time.

Netflix has an option to download files offline, as will this sim with scenery files. If you don't have enough bandwidth available, your Netflix video will start buffering. If you don't have a fast enough internet connection, you can't download 4K video. Online, many videos will simply lower the video quality to match your speed. That is why performance is dependent on Internet speed if you don't download the scenery ahead of time.

The popping is from the local computing limitations, just like every other sim and game. The issue is how to hide what the computer can't render in time. Some games use haze for example. Developers are getting more creative, but video cards can still only push out so many polygons. Realistically there's going to have to be some limit.

The fact that the game can be played offline once you've downloaded the scenery basically shows nothing's happening frame by frame via the Internet.

[SteveW 1,792]

2.5G wi-fi can deliver 1080p video to at least one node in a regular household. With the new sim. the scenery textures are downloaded in the resolution that can be coped with. Latency is not an issue as it might be with killing games.

[Mike T 208]

3 hours ago, simbol said:

You need to get your maths rights:

Wired Connection = 1ms:

10.22 MB/sec = 85.73 mbps.

Now a wireless connection with 20ms RTT, which is just only 19ms more in delay than a wired protocl:

2.54 MB/sec = 21.47 mbps

From 1ms to 20ms it means a 75% performance drop. TCP/IP is massively affected by Round Trip Time. It is a flaw of this protocol.

You can find lots of information about why TCP/IP suffer from these issues here: https://wiki.geant.org/display/public/EK/Welcome+to+the+eduPERT+Knowledge+Base, there are things you can use to reduce it like Windows Scaling, Traffic Shaping, etc. but bottom line nothing beats a wired connection.

I agree, but it seems some users are trying to understand the differences between wired and wireless. I hate to see people discrediting information posted by other users without having relevant data.

Maths don't lie, the entire world of mathematicians have been trying to invent a new network protocol to replace TCP/IP in order to increase the performance of our networks, TCP/IP was invented back in 1970s by 2 incredible DARPA scientists, the protocol is fantastic but it was never designed to withstand high speed throughput over long distances, the purpose of the protocol was to deliver the information in a reliable way. To put things on perspective the first network was a Local Area Network (LAN) and supported only 2.94 Mbps.

In case you are curios, big ISP providers do not run their networks using TCP/IP. They use SONET (Synchronous Optical Networking) and other advanced protocols as a higher encapsulation layer in order to overcome all the limitations TCP/IP have. Unfortunately SONET and such protocols can only be used by very specialized equipment and not  by our home devices.

Big corporations implement traffic shaping using MPLS channels between two distant sites, with this technique they can increase the default TCP Windows Scaling Factor after leaving their LANs for a much larger value, this allows them to alter the mathematical equation for TCP/IP throughput and in turn they obtain much better performance between their sites despite of how far they are. So yes there are solutions for these issues but they are not easy to implement or cheap.

Regards,
Simbol

Hi Simbol:

Not to call you out, but there is a lot wrong with your post and I wanted to clarify a few things:

1. MSFS will be using a streaming protocol to send data to our PCs in real time. Real time streaming protocols use UDP/IP and not TCP/IP. UDP is a connectionless protocol which removes the overhead for connection oriented protocol like TCP. Why? TCP wants the dataflow to be reliable so it verifies that each packet in a flow is received and sequenced which adds latency. TCP is used for common protocols like HTTP(S) (web) and SMTP (email) because it doesn't matter if your website loads in 50ms or 100ms.  On the other hand real time protocols (RTP) like VoIP, Video Over IP, and streaming applications like MSFS would lag badly if TCP were used because unlike your web browser which sends a few large packets and then it's done, RTP uses lots of small packets which makes TCP impractical. With UDP, packets are sent and not checked by the protocol. Rather, the magic is done in the application layer to verify packets are received properly. There are other techniques that will also help conceal latency and jitter and can make use of your much faster CPU on the PC and not be limited by the capabilities of the NIC. This is why you can have YouTube and Hulu stream all day and despite variable latency on the internet the quality is great even at 4k or 1080p, and 5.1 sound. MSFS will be able to do the same. Also, MS will use packet deduplication to minimize the stream as much as possible, in addition to minimizing what must actually be sent to you vs what's already loaded from local gigs of data on your HD.

2. You refer to WIFI as its a homogeneous entity and it is not. Wifi performance will depend on the type of Wi-Fi being used - 802.11g (gasp), 802.11n, 802.11ac, 802.11ax - AND it will also depend on how many spatial streams the WIFI access point supports as well as the chipset in the client, interference, how far you are from the AP, etc. Most new consumer APs running 802.11ac have a max theoretical connection speed of 1.3Gbps or 1.8Gbps at 5Ghz. But that is under the best conditions with 2 or 3 spatial streams respectively. Most clients will  likely get between 300 and 800Mbps - which is fine. But remember, an AP acts like a hub. The more devices connected to it, the higher the latency since each device gets a time slice to transmit. BUT, to be clear Wi-Fi is ABSOLUTELY not as reliable as a wired connection.  Why? As I said, an AP is a hub. The more devices connected, the lower the bandwidth available per each device, and the higher the latency. ALSO, the further you move away the lower your bandwidth. With 5Ghz, you have much shorter range than 2.4Ghz, and you have less ability to penetrate obstacles like walls. Finally, while not so much of an issue at 5Ghz due to the wider range of channels, Wi-Fi is subject to interference especially at 2.4ghz. In highly dense Wi-Fi environments such as large apartment buildings and complexes, getting optimal bandwidth is nearly impossible unless you have enterprise grade equipment.

3. SONET is a protocol but it is very 2001 and not really used :-). Modern networks are built using fiber but use IP not SONET (or ATM :-). Also, WAN protocols are layer 2 so your TCP/IP analogy doesn't apply since you're mixing layers. TCP is layer 4 and IP is layer 3. That's why TCP/IP has to be encapsulated over a layer 2 network, but its okay, modern MPLS networks (also layer 2) handle this stuff at very low latencies. The underlying network is not concerned with your TCP/IP or UDP/IP traffic. So you've badly mixed up TCP and SONET since they are totally separate protocols.

4. Finally, MPLS has absolutely nothing to do with Windows scaling - that's something that's restricted to the LAN. If you're referring to being able to support jumbo frames which are above any packets above 1500 MTU (Jumbo Frames), you don't do that over your WAN and neither do you have a reason to. Why? If you increase your frame size above the standard, the egress router will simply break it down into 1500 byte fragments. And since jumbo frames have to be implicitly turned on - and the Internet does not have them turned on, you'd actually make your network slower. MPLS actually acts like a VPN. MPLS packets are encapsulated and encrypted but again, it doesn't care what the payload is: TCP, UDP, RTP, or something else. 

5. You're greatly overestimating the impact of layer 4 protocols like TCP on latency and WiFi doesn't add anywhere near 50ms to the network. I can ping a resource across the country or across the Atlantic in less than 100ms. Azure is built so that sessions connect to the closest datacenter. Azure has 54 regions and they're in 140 countries. I can promise you that unless you're in Antartica, Greenland, certain parts of Africa or Central Russia you can get to an Azure DC in well under 100ms. Depending on the quality of your connection of course.  Anyhoo, TCP/IP is the global standard on which the Internet runs. It's not problematic at all. Modern networks are now a simple IP handoff whether it's your cable modem, DSL, Ethernet. 

In other words, if you want to best, and most reliable connection for MSFS 2020 do this:

1. The more bandwidth you give IP the more bandwidth it will take - get the most bandwidth available - or that you can afford

2. Wired is more reliable than wireless. If don't have wireless capable of 5Ghz and multiple spatial streams, simply plug directly into your router. Unless you have a bad cable, you'll always connect at the highest speed and don't have to worry about interference. 

3. Upgrade your wireless router to 802.11ac or 802.11ax. If your router say 802.11b,g, or n...that means you!!!

4. Don't take that job in Greenland 🙂

Hope this helps, and sorry for calling you out, and the long post but this applies directly to MSFS performance and should be correct.

Regards

Mike T.

Edited October 15, 2019 by Mike T

[simbol 5,820]

You don't know if they will use TCP/IP or UDP. UDP will be a disaster if a packet get missed it will not be resend, meaning you would get all sort of issues, IE AI models jumping location, multiplayer users jumping locations, missing tiles on your scenario, etc.

Never said SONET would be used by MS read my post again. 

Issue is throughput no connection speed, I explained about geolocation a couple of posts ago seems you miss it.

I can take any job I want by the way, often I turn down proposals in Greenland, too far from my family. No idea what do your intentions are with such comments.

The argument is, wired is faster than WiFi it seems nobody can get it.. Nothing goes faster than having a piece of cable attached to it.. Why is it so difficult to understand?  

Topic should be locked, nobody gets the point and we are wasting everyone times and AVSIM resources.

S.

Edited October 15, 2019 by simbol

[dojjan 3]

Hey man,

Connect to your wifi, open up cmd and run this command:

netsh wlan show interfaces

Show us the output and we can decode it for you.

PS. I've got 3.8ms avg to google DNS using wireless (802.11ac)

[vortex681 806]

The bottom line with the wifi argument is that it doesn't matter how fast your wifi connection is, even if you have a router capable of 1Gbps with the fastest wifi possible (and you're the only person connected to it), you'll still be limited to the maximum bandwidth your ISP connection allows. The newest, most expensive high tech routers are all well and good but if the maximum bandwidth you pay for is 50Mbps, that's all you'll ever get from your Internet connection on the best day, wired or wireless.

 

[MattNischan 3,778]

6 hours ago, simbol said:

The argument is, wired is faster than WiFi it seems nobody can get it.. Nothing goes faster than having a piece of cable attached to it.. Why is it so difficult to understand?  

Because that wasn't the argument. The claim was that WiFi will not be sufficient or recommended for the new MSFS. There's nothing about the apparent engine design nor characteristics of WiFi connections over wired in this scenario that would warrant that recommendation. We agree that a WiFi connection is not superior to a wired one and that RTT has an impact (sometimes significant) on TCP/IP bandwidth capacity. I am well aware of the math. That was not my claim, as I already stated in my last post. There's no need to flex here; I'm just a chill dude offering my advice knowing the subject area both from a practical and technical standpoint. The claim that a WiFi connection will not be sufficient for MSFS is unwarranted, and there's no need to whip people into a tizzy getting them thinking they need to go get expensive gigabit routers and hook wires up just to stream a little scenery data.

The thing is, from a practical reality standpoint, the latency to the server will always swap the latency that your radio, which is feet away, will add. And if the average WiFi connection was indeed such a horrible worst case as is being claimed, nobody would be streaming Hulu to their laptops and tablets.

I don't understand the necessity for tech folks to claim the sky is falling. Everyone relax, WiFi will be just fine for this purpose. That's all I was saying. No need for the bad vibes, seriously.

Rob, simbol, if it turns out I'm wrong, I'll send you both a bottle of a booze of your choosing, up to $100. Truce?

[irrics 1,517]

Again, why is this topic in the MSFS area?

 

[Paraffin 2,197]

1 hour ago, MattNischan said:

Because that wasn't the argument. The claim was that WiFi will not be sufficient or recommended for the new MSFS. There's nothing about the apparent engine design nor characteristics of WiFi connections over wired in this scenario that would warrant that recommendation.

I think what's being missed in this discussion is edge-case situations with slower connections.

If you're on a relatively slow ISP connection, you might get the highest quality scenery on a PC with a direct Ethernet connection. Meanwhile, your laptop PC on slower WiFi might get slightly lower quality scenery if it can't pre-fetch and buffer the scenery as fast as the hardwired connection. 

Another possible impact with slower connections is that a PC on Ethernet might need less hard drive space to pre-fetch and buffer the scenery, compared to the buffer space needed on a laptop with a the WiFi running slower on the same network.

In these situations with slow ISP connections, it might be reasonable to recommend hardwired Ethernet instead of WiFi, if it allows slightly better quality scenery, or frees up a little more of your hard drive space. If you're on a fast ISP connection with plenty of overhead and not too many other users on the network, then it won't matter whether you're on a hardwired connection or WiFi. 

[Paraffin 2,197]

7 minutes ago, irrics said:

Again, why is this topic in the MSFS area?

Because the new MSFS is the only flight simulator that will be using this new streaming scenery paradigm in such a data-intensive way. It's relevant to this sim, and no other one.