TCP settings?

Hello!

I'm sure at first you'll think this should be on a different forum - probably the "running windows on mac" forum, but stick with it, it's really a mac systems question in the end.

I do a lot of work my connecting to windows servers through RDP. My employer purchased a MacBook Air (running 10.7.2 lion) for me - very nice! I've really enjoyed the mac experience. The shell is great, the gesture pad is wonderful. Combined with the multi-desktop structure, and the never-ending battery life (since its all solid state), it is a great improvement in productivity.

Nevertheless, RDP performance has been downright horrible. By "horrible" I mean mainly keyboard latency. There is latency between typing the key and seeing it show in the RDP session. I tried RDC. I tried CoRD. All are very latent. I tried connecting to WIndows 2003 Server, and Windows 2008 server - no difference. I am connecting from work, with a huge pipe - the bandwidth is off the meter if I go to any of the speed test sites.

I finally gave up on any mac client (looks it is not supported for lion according to MS site) and installed Windows 7 on a virtual (VMWare Fusion). The virtual runs very well! EXCEPT - when I run RDP. Just before I shot myself in the face, I tried one more thing that cleared up the keyboard latency in a special case.

I have one network I connect to through a SonicWall VPN client. I installed this client on the Windows 7 virtual. If I run the VPN client, connect to the remote server through the VPN client, the keyboard latency vanishes - completely! It becomes lightning fast. Since I connect to only this particular network through SonicWall, I am desperate to find out why this particular configuration would help RDP so much. I do most of my work without connecting through this VPN (raw RDP to Windows servers).

Question: the virtual is using the mac host for network connectivity, and usually going through a VPN causes network performance to decrease... yet in this case, there is a vast improvement when it comes to RDP. Does anyone have a theory as to what SonicWall does to push these RDP packets through? Could it change some of the mac os network settings specifically for the virtual network adapter? If so, what do you think those might be?

I have tried (system variables):
net.inet.tcp.rfc1323 = 0 (turning this off, default is on 1 )
net.inet.tcp.delayed_ack = 0 (default is 3)
As well as various recv and send buffer settings

Remember, this is a Windows RDP client running on a windows virtual Windows 7 x64. SonicWall = on, awesome performance. Normal RDP = bad keyboard latency. It seems that it would have to be something in the mac network settings.

Thanks!

I have a 2009 MBP with Lion 10.7.3. I'm a heavy CoRD user and I travel to many sites as well as access many sites remotely whether it be port forwarding or a variety of VPN configurations. I've also used MSTSC as well as Remote Desktops (Admin Tools) and Remote Desktops Manager v2 in a Win7 Ultimate 64bit Fusion 4.1.2 VM.

Unfortunately I told you all of that to tell you this. I have no answer for you. There are some sites that work better that others, but as a whole I would say that it isn't CoRD that is the problem. Can you connect to the SW VPN with the Mac NetExtender client from SW? Does the latency go away with a direct Mac VPN connection and CoRD?

Have you tried the USB to Ethernet adapter for the Air?

MacsWork said:

I have a 2009 MBP with Lion 10.7.3. I'm a heavy CoRD user and I travel to many sites as well as access many sites remotely whether it be port forwarding or a variety of VPN configurations. I've also used MSTSC as well as Remote Desktops (Admin Tools) and Remote Desktops Manager v2 in a Win7 Ultimate 64bit Fusion 4.1.2 VM.

Unfortunately I told you all of that to tell you this. I have no answer for you. There are some sites that work better that others, but as a whole I would say that it isn't CoRD that is the problem. Can you connect to the SW VPN with the Mac NetExtender client from SW? Does the latency go away with a direct Mac VPN connection and CoRD?

Have you tried the USB to Ethernet adapter for the Air?

Click to expand...

@MacsWork:

Thanks for responding. Actually, I've posted this problem in other forums as well, and even with hundreds of people viewing the threads, you are the first to respond. So, for that, Thanks!

I do not think CoRD is the issue. I do not think RDC is the issue, either. Rather, I think its something fundamental to the Mac OS, which is why my thread ultimately ended up here. I say this because after giving up on the RDC and CoRD, I figured installing Windows 7 on a virtual and using the actual Microsoft client would clear things up - and it did not. The Windows 7 virtual is a guest virtual on the mac host. Also, if I dual boot the mac to Windows 7, the problem clears up. There is something going on with the Mac OS...

Also, I know it not an issue of one RDP site (server) being faster than another. I can put the MacBook Air to my left, connected to the work network (getting 70 Mbps), and a PC to my right, also connected via the work network - then RDP both machines, at the same time, to the same server, and the performance when typing is like night and day.

Sure, the mac "works" - that is, I can connect, and I can type and I can, if I fight through it, do the work. However, it makes it very painful. I connect to these servers, not really to administrate them (just doing a bunch of clicking); Rather, I connect to them to do programming. So the bulk of my time is spent typing. I would much rather see the keyboard performance high.

Also, in case you are wondering, on the remote session, I'm not typing into anything special - its just notepad.

This is why I ultimately posted to the Mac OS forum - because it doesn't really seem to be an RDC or CoRD isssue - or even a MSTSC.exe (running in Virtual issue). When the Mac OS is involved, then all RDP from any program has poor keyboard latency. Its not a hardware issue too because if the hardware is booted to Windows 7, the performance is great. Also, there is that one special case of SW VPN client, running on the Windows 7 virtual that made it all work all of a sudden.

My question is - what in the world could that SW VPN client be doing (to the mac tcp/ip stack?) in order to clear up the keyboard latency? What is different about RDPing through that? I don't know the answer to that question, and if you don't either, that's fine - I'm just wondering if anyone has any theories. If you have a theory, I'll go test it - keeping in mind that I don't have a lot of funds to buy extra stuff to do the testing. Time - yes. I have not been able to test the SW mac VPN client because it is not free. I don't want to spend a couple hundred dollars . The windows one is free from SW, which is why I eventually tested it from the virtual - and it cleared things up, to my surprise.

Thanks!

MacsWork said:

I have a 2009 MBP with Lion 10.7.3. I'm a heavy CoRD user and I travel to many sites as well as access many sites remotely whether it be port forwarding or a variety of VPN configurations. I've also used MSTSC as well as Remote Desktops (Admin Tools) and Remote Desktops Manager v2 in a Win7 Ultimate 64bit Fusion 4.1.2 VM.

Unfortunately I told you all of that to tell you this. I have no answer for you. There are some sites that work better that others, but as a whole I would say that it isn't CoRD that is the problem. Can you connect to the SW VPN with the Mac NetExtender client from SW? Does the latency go away with a direct Mac VPN connection and CoRD?

Have you tried the USB to Ethernet adapter for the Air?

Click to expand...

@MacWorks:

I downloaded NetExtender from here: Secure Designs, Inc - Sonicwall SSL-VPN NetExtender Mac

However, it did not work with the SonicWall VPN peer - could not connect.

Thanks! dfrulla

As for the TCP stack,...

I doubt SW VPN is changing the stack. It may however be prioritizing the packets.

Perhaps all the multicasting the Mac is doing on your network with Bonjour and such the sheer volume of traffic that it creates may be flooding the switch port.

Try this...

Disable Bonjour by turning off mDNSResponder

MacsWork said:

As for the TCP stack,...

I doubt SW VPN is changing the stack. It may however be prioritizing the packets.

Perhaps all the multicasting the Mac is doing on your network with Bonjour and such the sheer volume of traffic that it creates may be flooding the switch port.

Try this...

Disable Bonjour by turning off mDNSResponder

Click to expand...

MacWorks, thanks for the response! I have disabled the service and the RDP performance improved - slightly. If I am typing in the RDP session, I am still pulling ahead of the text appearing on the screen about 2-3 words. I don't really type that fast. I'm OK. I type faster while coding because that is what I am used to. But even if I type in notepad, I pull ahead because of the latency.

But I did notice a slight improvement

While the service is off, I can't use and DNS...

Thanks,
dfulla

Na mas.

Sorry.

MacsWork said:

Na mas.

Sorry.

Click to expand...

MacsWork:

Thanks for your responses. I finally figured it out! It is a combination of things. I think I was right, however - there is something going on with the Mac OS with RDP, but I was able to get around it on the virtual. I didn't realize it, but the VMWare defaults the virtual network adapter to be NATed - sharing the mac's network connection. But by changing the adapter to use a bridged connection (connect directly to the physical network), all the latency clears up. I still can't get RDC or CoRD to behave correctly - perhaps there is something there that Microsoft and CoRD needs to address with lion.

I'm still not sure why using the SW VPN client in the virtual cleared it up (when the VMWare adapter was still set to NAT). But oh well - it took me a couple weeks, but I have the solution - a virtual Windows 7, using a bridged connection.

Thanks! Hopefully this will help others if they experience the same thing!
dfrull