Edge Router Lite Possible Problem

[coxhaus]

I came across this thread and it seemed interesting. It seems if the UDP packets get bursty then they arrive out of sequence and are considered a lost packet. I could see this affecting gaming and TV and anything with UDP.

https://community.ubnt.com/t5/EdgeMAX/UDP-packet-loss-with-EdgeRouter-Lite/td-p/1343012

 

[netwrks]

A work around was added to v1.9.7alpha1.

 

[sfx2000]

I came across this thread and it seemed interesting. It seems if the UDP packets get bursty then they arrive out of sequence and are considered a lost packet. I could see this affecting gaming and TV and anything with UDP.

More of an application thing perhaps - UDP is unreliable, expect packets to come out of sequence, and also missing packets.

The server and client need to deal with things at the application layer of the protocol stack when using UDP...

 

[coxhaus]

UDP is made for streaming so it does not have built-in error correction like TCP. But UDP packet sequencing is still important especially with multiple CPUs. The problem is when the ERL is removed the packets are in perfect sequence.

 

[sfx2000]

UDP is made for streaming so it does not have built-in error correction like TCP. But UDP packet sequencing is still important especially with multiple CPUs. The problem is when the ERL is removed the packets are in perfect sequence.

UDP is UDP - streamers like it as it reduces overhead - which can be much if one were to do the same app over TCP...

Fair enough - if the lower layers are mangling things... but that mangling could happen anywhere, not just within the ERL...

The ERL might be an edge-case here...

But within the OSI stack, the applications need to be able to react appropriately - sorry to get all greybeard - but this is somewhat of an application issue - and the developers should know this...

 

[sfx2000]

The ERL might be an edge-case here...

I could see one interesting impact - OpenVPN if one is using UDP there (the default) - and again, apps need to deal with packet mangling...

 

[coxhaus]

Sounds like to me from reading the forum they think it is a kernel problem in the ERL and multiple CPUs are compounding it. The ER-X does not have this problem but some of the others do. Maybe they will move to one of the newer kernels.

Yes I would think VPN would be included with the issue.

Yes getting the packets back in order is a basic routing function. It is why we pay Cisco, Netgear and all the other companies money.

 

[sfx2000]

Sounds like to me from reading the forum they think it is a kernel problem in the ERL and multiple CPUs are compounding it. The ER-X does not have this problem but some of the others do. Maybe they will move to one of the newer kernels.

Yes I would think VPN would be included with the issue.

Yes getting the packets back in order is a basic routing function. It is why we pay Cisco, Netgear and all the other companies money.

SMP is always interesting - AMD's Ryzen's seem to have a problem with parallel builds on GCC these days...