Asus RT-AC68U cannot handle 1000 Mbps IPTV connection

[grahamgo]

Just changed internet provider. Currently on their 1000/1000 mbps package, a 2000 mbps package is also available. They supply a fiber-optic to Wan converter box feeding a router type ZYXEL model TMNL-555A81.

Using this setup I do get a full 1000/1000 LAN connection. However, the router is locked down and is not suitable for use with my NAS (for instance). I, therefore, decided to use my Asus RT-AC68U router. I can get it to work perfectly well by connecting it to the Media Converter. Using the LAN-IPTV-Manual VID 300 setting.

The problem is that it only delivers 300/300 mbps on the LAN. I notice that when I perform a speedtest CPU Core1 goes to 100% and Core2 stays around 15% which seems odd. I have tried earlier Merlin builds, even Tomato. But nothing helps. I have even tried overclocking (unsuccessfully).

So conclude that either the IPTV routines are not optimized, or my RT-AC68U is underpowered.

My question, I am happy to buy a new ASUS router (I like Merlin). But I cannot find a site that help me choose a router with a better CPU, or perhaps a router with better IPTV hardware. I would appreciate any help or comments.

 

[ColinTaylor]

Without NAT acceleration being enabled your router will be limited to those speeds because it is CPU-limited (and single threaded).

I suspect the reason that NAT acceleration is not being used is because of you using IPTV. As an experiment I suggest that you temporarily disable IPTV, and reboot the router. With NAT acceleration now enabled you should be able to get a throughput of 900+ Mbps with almost zero CPU usage.

 

[cremes]

I had a 68U that was also underpowered for my ISP gigabit connection. It maxed out around the same numbers (300 down, 40 up). I bought a 86U and it gives me the full 940 down and 40 up on my cable gigabit link.

The 68U is just underpowered these days. It's a 1 ghz dual core processor whereas the 86U (and other Asus models) now use a 1.8 ghz processor (I think they are still 2-core).

 

[RMerlin]

I had a 68U that was also underpowered for my ISP gigabit connection. It maxed out around the same numbers (300 down, 40 up).

That means you had hardware acceleration disabled. An RT-AC68U is able to reach full gigabit performance.

 

[grahamgo]

Guys, thank you very much for your advice. I did in fact find that QOS was turned on, causing the NAT acceleration to be turned off. But now it's on "CTF (Cut Through Forwarding) is enabled" The performance is much improved, I am now getting about 500 mbps up/down, see attachment.
However, this is still about 50% less than the router supplied by my ISP. I assume that this is the best that the 68U can achieve. Probably its something to do with having to use the IPTV in VID 300 PRIO 0 to select internet from the incoming fibre stream ?

Possibly I should consider buying the 86U ?

In reality, of course, I can live with 500/500 but the full 1000/1000 would be nicer especially for the NAS.

 

[a5m]

I don't know if you're referring to AT&T Fiber, but we have their Gigabit service and I was getting ~940 Mbps up/down with the RT-AC68U.

I use a VPN so soon after switched to a RT-AC86U, which has been a much welcomed improvement all-around. The 68U was good, but the 86U is worth the upgrade.

 

[5stringdeath]

In reality, of course, I can live with 500/500 but the full 1000/1000 would be nicer especially for the NAS.

I'm confused. That speedtest is your WAN speeds. Isn't your NAS on your LAN? It should be able to do gig throughput despite what Speedtest is showing for your internet speed, unless you are talking about a remote box.

 

[grahamgo]

The connection is incoming Fiber -> Media converter -> RT-AC68U -> testing PC This is a T-mobile home internet 1000/1000 mbps

@a5m Hi, Then I really don't know what I am doing wrong, If I connect the T-mobile supplied router I get the full speed on the PC, actually 980/975 when tested. If I substitute RT-AC68U I get 440/515 The AC68 is running Merlin 384.15

@5stringdeath Hi, correct I am only testing the internet performance. I am pretty confident the internal LAN (NAS) is running at 1gh/z

I'm thinking to try using a Netgear GS105E ahead of the 68U to offload the IPTV Vid300 function.

 

[miroco]

Consider a Netgear GS105Ev2 Gigabit switch or similar and stick with the rt-ac68u. The rt-ac86u is not well suited for IPTV tasks, and that may be the case for all models built on the new platform.

https://www.asus.com/us/support/FAQ/1011708/

https://www.snbforums.com/threads/r...t-forwarding-igmp-snooping.47201/#post-511930
https://www.snbforums.com/threads/r...384-11-is-available.56501/page-38#post-492128

 

[cremes]

Guys, thank you very much for your advice. I did in fact find that QOS was turned on, causing the NAT acceleration to be turned off. But now it's on "CTF (Cut Through Forwarding) is enabled" The performance is much improved, I am now getting about 500 mbps up/down, see attachment.
However, this is still about 50% less than the router supplied by my ISP. I assume that this is the best that the 68U can achieve. Probably its something to do with having to use the IPTV in VID 300 PRIO 0 to select internet from the incoming fibre stream ?

Possibly I should consider buying the 86U ?

In reality, of course, I can live with 500/500 but the full 1000/1000 would be nicer especially for the NAS.

I left off a detail in my original response. When my gig cable was only delivering 300Mb, the gateway I had (from Xfinity) was in bridge mode. I wanted my router to handle all the public-facing work and I needed to avoid a double-NAT situation for my Plex server.

Turns out the gateway (I forget the model) was pretty much crippled when in bridge mode. (BTW, a "gateway" is a combo modem/router in case y'all didn't know.)

When the gateway was in its router mode, I could get the full line rate. When bridged, it was about a third of the performance.

I don't know if you have a similar situation, but look at that before dropping any $$ on a new router.

If you can't solve it, then reduce your ISP package/bill. It's nuts to pay for a gig and only get half.

 

[El Mariachi]

I left off a detail in my original response. When my gig cable was only delivering 300Mb, the gateway I had (from Xfinity) was in bridge mode. I wanted my router to handle all the public-facing work and I needed to avoid a double-NAT situation for my Plex server.

Turns out the gateway (I forget the model) was pretty much crippled when in bridge mode. (BTW, a "gateway" is a combo modem/router in case y'all didn't know.)

When the gateway was in its router mode, I could get the full line rate. When bridged, it was about a third of the performance.

I don't know if you have a similar situation, but look at that before dropping any $$ on a new router.

If you can't solve it, then reduce your ISP package/bill. It's nuts to pay for a gig and only get half.

If you absolutely must use your ISP provided box in router mode you can try this:

1. Plug a cable form a LAN port of the ZYXEL box to the WAN port of your ASUS router
2. In your ZYXEL box assign your ASUS router a static IP address
3. In your ZYXEL box go to the DMZ page and add that static IP address to the DMZ

With the other NAT acceleration settings configured in your ASUS router try your speedtest again.

Although not a perfect solution, this should solve most double NAT issues. I use this for my fail over WAN which needs router mode enabled to function such as in your use case.

 

[grahamgo]

@miroco Thanks for the info. I do have a GS105e and will try it, but I have decided to go a different path, see below.

@cremes Unfortunately T-Mobile does not allow bridge mode. As to cost, well we have a combo deal. home internet €22 p/m + two mobile phones SIM only, unlimited data €35. Total cost €57 p/m. But if I reduce the internet speed, the combo package is no longer valid, and the cost increases. Silly, but that's how it is.

@El Mariachi I actually did try this early on, it works, unfortunately, I do end up with a double NAT situation. So gave that idea up.

I have decided to keep my RT-AC68 router, which is excellent, I have decided to purchase a Router Ubiquiti Networks ER-X-SFP a 5 port none wifi router with SFP fiber input at €65 its less expensive than upgrading the Asus router and should provide the performance. Thanks for all the help and hints, it nice to get so much useful info.