PING - time delay

You are pinging a server that is probably a bit busy serving files, applications, applications etc. You are seeing a small delay of less than 20ms - not a big issue. Is the server under heavy load? If you try the ping at 8pm (some people will have left), is the delay then maybe less?

When I ping one of my servers at home or a NAS - I get 1ms responses as well.

Did you run all that VMs on NIC or you balancing traffic with more than one
Did you face this delay when you ping PC to PC none VM
Do you use any wifi connection between PCs and VMs

(1) "a server that is probably a bit busy serving files" --> there are only two users in the office. But SBS2011 is a virtual machine which is built on slow SATA hard drive (Not SAS or SSD).
(2) "the ping at 8pm" --> I will try that  this evening.
(3) "Did you run all that VMs on NIC" --> Yes.
(4) "delay when ping PC to PC none VM" -->Yes. same result when I pinged standalone PC from another standalone PC.
(5) "wifi connection between PCs and VMs" --> No

I manage several other networks and this is what I just found "for the first time".
(1) I performed PING in standalone server environment ( no Hyper-V or VMWare ) and I get <1ms consistently.
(2) I performed PING in two VMWare networks and I get <1ms 99% of the time.
(3) I performed PING in another Hyper-V environment and I get delays.

So based on my PING testing in VMWare, Hyper-V, and standalone server environment, hyper-V is the worst.
The reason for PING test was because in this network, we have Terminal Server(named TS1) where users opens Quickbooks files from "APP1" server and QB files are crashing. When I called QB tech support, they indicated that there is a delay on the network and it is causing QB file crash.
I rebooted both TS1/APP1/SBS2011 multiple times, but the delay won't go away. I suspected "Network Switch" initially and power cycled 16 port network switch, but the result was the same. I was going to replace the switch, but after performing PING test on another Hyper-V site, I am so sure if this delay problem will go away with new switch.

Do you use a Gigabit switch?
You should be
Trying to check your network traffic using wireshark or something like that to define what's going on in the network
If you're using any firewall system or antivirus app try to pause it and test

I am using Gigabit switches.
This may be expected in Hyper-V environment??

Do you experience any performance issues other than the fact that you see a lower ping?

How much memory and cpu does your SBS VM have?

SBS2011 VM: 16GB
Terminal Server VM: 6GB
QB APP Server VM: 4GB

Update:
Everything seems to be running just fine according to the user after disabling Windows Firewalls for Private Profile and Public Profile. The user said that it is running faster too, let alone QB does not crash anymore.

Disabling a firewall would improve speed, that's what I'd expect. However, disabling the firewall resulting in 'normal' pings is strange, a firewall would either block or not block ICMP traffic (ping), not slow it down.

Crashing an application like QB is something that can happen when a firewall is not configured properly, like when it blocks one or more ports that are needed by the application. Configuring it properly would have also fixed the crashing issue.

But good to hear that things worked out for you.

"a firewall would either block or not block ICMP traffic (ping), not slow it down." --> I agree.
"QB is something that can happen when a firewall is not configured properly'" --> true. I thought that we got QB tech support take care of opening necessary ports on QB server. Looking back, I remember installing Symantec EndPoint Protection software in order to scan these servers to make sure they were not infected and that is when these Firewall settings were changed. They have used QB for a couple of years without a problem.

Since I disabled firewall for public and private, PING response time returned to normal <1ms.