Buffering over network, and then again .... not really

[Josef_Aarskov]

Hi, there

I’m having a somewhat strange buffering issue, that I’m hoping some of all you good people know how to fix.

I just bought a Vero 4K+, that I’m about to implement as a replacement for my trusty Raspberry Pi 2 running OSMC, as I’m upgrading to a 4K projector in a bit. Both are connected to my movie library spread across 2 Synology NAS servers via a Gigabit ethernet switch and a Gigabit router.

NAS 1 (old) is full of 1080p movies, and therefore I got NAS 2 (new) alongside it, which has quite a bit more space, also for upcoming UHD material.

The issue I’m experiencing is massive stutter and buffering issues, when playing back 1080p movies on the Vero 4K+ from my old NAS 1, be it high bitrate remuxes or not. Everything without exception plays back like crap. However, when I play back material residing on my newer NAS 2, I have no problems whatsoever, it also happily plays UHD HEVC rips with Atmos soundtrack, skips chapters without buffering issues and so on.

Now, the logical assumption would now be that its just my old NAS 1 is malfunctioning somehow, but the funny thing is, that when I tried playing back 1080p stuff from it via OSMC on my Raspberry Pi 2, there are no issues at all, and everything runs 100% smoothly, as it always did.

So it’s like the Vero 4K+ and my old RPi2 are using the same connection to both servers, but not with the same results, at least with one of them.
Both my RPi 2 and the Vero 4K+ are connected to the NAS servers via NFS.

Any guesses? I’m not into the whole log thing, so if that’s whats needed, someone will have to guide me … Anyway, I’m really at a loss here and could use help … Thanx in advance!

[Josef_Aarskov]

UPDATE: Tried connecting the Vero 4K+ directly to the router with a fresh cable, thereby ruling out bad cabling and/or ethernet switch, but alas, nothing changed

However, it seems I was a bit too fast stating that UHD playback from NAS 2 is flawless, as it can actually buffer a bit now and then, but it’s still nothing when compared to playback from NAS 1, which is still hopelessly lagging and stuttering, even with low bitrate 1080p.

[sam_nazarko]

What’s the make and model of NAS1?
There was a user with similar issues with an old Synology

[dillthedog]

If you’re familiar with command-line Linux, it would be useful to see:

1. iperf3 figures from the Vero4K+ to the older NAS, plus reverse-mode figures. (We can look at the new NAS later but let’s take one step at a time.)
2. ethtool information for the NAS network interface (probably eth0).

[Josef_Aarskov]

The older is a DS413j and the newer a DS418j

[Josef_Aarskov]

Oh wow … not something I’m super familiar with, but I’ll have a crack at it, if you can point me to some directions

[dillthedog]

Working with OSMC via the command line - General - OSMC

[How To] Check Network Performance with iperf3

Sometimes it is important to check the network performance between your OSMC Device and the device providing your media (NAS, Server, PC). Especially when you are connected via wireless the throughput variations can harm you viewing experience. This short How To should give you the required information how to install iperf3 and how to run the respective tests. When doing these tests it is suggested to have a simple setup (single switch between Sender and Receiver and avoid other traffic on the …

AFAIK, iperf3 isn’t installed by default on the DSM operating system, but it’s available here. I’m afraid I don’t have a Syno diskstation, so have no practical experience of installing this application.

[Josef_Aarskov]

Ok, I think I managed …

Here’s the output on the server side (Synology DS413j NAS)

admin@DiskStation:~$ iperf3 -s

Server listening on 5201
-----------------------------------------------------------
Accepted connection from 10.0.0.3, port 41144
[  5] local 10.0.0.10 port 5201 connected to 10.0.0.3 port 41145
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.01   sec  1.53 MBytes  12.8 Mbits/sec    3   4.24 KBytes       
[  5]   1.01-2.01   sec   385 KBytes  3.15 Mbits/sec    4   18.4 KBytes       
[  5]   2.01-3.00   sec  1.49 MBytes  12.6 Mbits/sec    4   25.5 KBytes       
[  5]   3.00-4.01   sec  1.09 MBytes  9.05 Mbits/sec    3   25.5 KBytes       
[  5]   4.01-5.01   sec  3.63 MBytes  30.4 Mbits/sec    4   25.5 KBytes       
[  5]   5.01-6.01   sec  3.26 MBytes  27.3 Mbits/sec    4   25.5 KBytes       
[  5]   6.01-7.01   sec   962 KBytes  7.88 Mbits/sec    4   24.0 KBytes       
[  5]   7.01-8.01   sec   973 KBytes  7.97 Mbits/sec    4   14.1 KBytes       
[  5]   8.01-9.01   sec  1.63 MBytes  13.7 Mbits/sec    3   24.0 KBytes       
[  5]   9.01-10.00  sec  5.04 MBytes  42.5 Mbits/sec    3   24.0 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  19.9 MBytes  16.7 Mbits/sec   36             sender
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------

And the client side (OSMC on Vero 4K+):

osmc@VERO4K:~$ iperf3 -R -c 10.0.0.10
Connecting to host 10.0.0.10, port 5201
Reverse mode, remote host 10.0.0.10 is sending
[  4] local 10.0.0.3 port 41145 connected to 10.0.0.10 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec  1.41 MBytes  11.8 Mbits/sec                  
[  4]   1.00-2.00   sec   399 KBytes  3.27 Mbits/sec                  
[  4]   2.00-3.00   sec  1.47 MBytes  12.4 Mbits/sec                  
[  4]   3.00-4.00   sec  1.11 MBytes  9.31 Mbits/sec                  
[  4]   4.00-5.00   sec  3.60 MBytes  30.2 Mbits/sec                  
[  4]   5.00-6.00   sec  3.28 MBytes  27.5 Mbits/sec                  
[  4]   6.00-7.00   sec   984 KBytes  8.06 Mbits/sec                  
[  4]   7.00-8.00   sec   925 KBytes  7.58 Mbits/sec                  
[  4]   8.00-9.00   sec  1.63 MBytes  13.7 Mbits/sec                  
[  4]   9.00-10.00  sec  5.06 MBytes  42.5 Mbits/sec                  
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec  19.9 MBytes  16.7 Mbits/sec   36             sender
[  4]   0.00-10.00  sec  19.8 MBytes  16.6 Mbits/sec                  receiver

Looks less than amazing, am I right?

[dillthedog]

You were quick!

The DS413j comes with a gigabit ethernet port, so, yes, the figures are not ideal.

Please also provide the output from running ethtool eth0 on the NAS.

(I’ve reformatted part of your post to make it more readable.)

Update: It looks like the two iperf3 tables are the output from the same command, just from a different perspective. Please provide the output from running iperf3 -c 10.0.0.10 on the Vero4K+.

[Josef_Aarskov]

Ok, I get this from the NAS:

Settings for eth0:

Cannot get device settings: Operation not permitted

Cannot get wake-on-lan settings: Operation not permitted

Cannot get link status: Operation not permitted

No data available

Hmmm … and regarding iperf, you mean I should reverse the process, right?

[Josef_Aarskov]

osmc@VERO4K:~$ iperf3 -c 10.0.0.10
Connecting to host 10.0.0.10, port 5201
[ 4] local 10.0.0.3 port 41189 connected to 10.0.0.10 port 5201
[ ID] Interval Transfer Bandwidth Retr Cwnd
[ 4] 0.00-1.00 sec 5.24 MBytes 44.0 Mbits/sec 77 4.24 KBytes
[ 4] 1.00-2.00 sec 2.99 MBytes 25.1 Mbits/sec 53 7.07 KBytes
[ 4] 2.00-3.00 sec 6.93 MBytes 58.2 Mbits/sec 79 8.48 KBytes
[ 4] 3.00-4.00 sec 5.04 MBytes 42.3 Mbits/sec 106 4.24 KBytes
[ 4] 4.00-5.00 sec 4.88 MBytes 40.9 Mbits/sec 77 4.24 KBytes
[ 4] 5.00-6.00 sec 4.02 MBytes 33.7 Mbits/sec 60 4.24 KBytes
[ 4] 6.00-7.00 sec 4.70 MBytes 39.5 Mbits/sec 75 4.24 KBytes
[ 4] 7.00-8.00 sec 4.10 MBytes 34.4 Mbits/sec 67 2.83 KBytes
[ 4] 8.00-9.00 sec 5.34 MBytes 44.8 Mbits/sec 97 4.24 KBytes
[ 4] 9.00-10.00 sec 5.53 MBytes 46.4 Mbits/sec 79 4.24 KBytes

---

[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-10.00 sec 48.8 MBytes 40.9 Mbits/sec 770 sender
[ 4] 0.00-10.00 sec 48.7 MBytes 40.8 Mbits/sec receiver

[dillthedog]

Are you logged on to the NAS as root?

@Josef_Aarskov

and regarding iperf, you mean I should reverse the process, right?

I mean you should provide the output from running the command iperf3 -c 10.0.0.10 on the V4K+. (No need to provide the output from the NAS.)

[Josef_Aarskov]

No, for some reason it will only let me log on as admin, although the password should be the same for root … Is that a problem?

[dillthedog]

It’s difficult to say, since I don’t have a Syno NAS, but the output from running ethtool is unexpected. What’s the output from running ifconfig?

As you can see, the speed from V4K+ to the NAS is better, though only averages around 41 Mbits/sec and is highly variable.

[Josef_Aarskov]

From ifconfig:

eth0 Link encap:Ethernet HWaddr 00:11:32:1B:89:D9
inet addr:10.0.0.10 Bcast:10.0.0.255 Mask:255.255.255.0
inet6 addr: fe80::211:32ff:fe1b:89d9/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:710444 errors:0 dropped:0 overruns:0 frame:0
TX packets:2259446 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:532
RX bytes:130634253 (124.5 MiB) TX bytes:3207035892 (2.9 GiB)
Interrupt:11

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:861 errors:0 dropped:0 overruns:0 frame:0
TX packets:861 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:125767 (122.8 KiB) TX bytes:125767 (122.8 KiB)

[dillthedog]

Apparently DSM 6 has been hardened: login - Synology DSM - Can't log as root (but works with admin) - Super User

Try sudo -i to switch to root

[Josef_Aarskov]

Ok, that worked … And then …?

[dillthedog]

And then ethtool eth0

[Josef_Aarskov]

Ok, here we go:

root@DiskStation : ~ # ethtool eth0

Settings for eth0:

Supported ports:

Supported link modes: Not reported

Supported pause frame use: No

Supports auto-negotiation: No

Advertised link modes: Not reported

Advertised pause frame use: No

Advertised auto-negotiation: No

Speed: 1000Mb/s

Duplex: Full

Port: MII

PHYAD: 1

Transceiver: internal

Auto-negotiation: off

Supports Wake-on: g

Wake-on: d

Link detected: yes

[dillthedog]

@Josef_Aarskov

Both are connected to my movie library spread across 2 Synology NAS servers via a Gigabit ethernet switch and a Gigabit router.

Is the older NAS connected to the switch or the router? And, if the switch, is is a managed switch?