subnet musk and ping question

(OS-windows xp prof.)
IP address 172.26.0.7
subnet musk 255.255.255.192
default gateway172.26.0.1

there are two question about it.first, is the subnet musk right? because when he configure the internet connection then he put IP address which is 172.26.0.7.then he go to subnet musk.automatically the subnet value put in to it. that is 255.255.0.0. but he put the value that is 255.255.255.192 .

another question is that ,when i ping in default gateway then the ping show

Reply from 172.26.0.1: bytes=32 time=4ms TTL=53
Reply from 172.26.0.1: bytes=32 time=4ms TTL=53
Reply from 172.26.0.1: bytes=32 time=3ms TTL=53
Reply from 172.26.0.1: bytes=32 time=5ms TTL=53

what is the mean of that  time=5 ms or 4 ms.
plz tell me

1.  Subnet Mask.  The subnet mask is fine.  The IPv4 address "172.26.0.7" is a "Class B" address based upon the value of the first octet "172".  The default subnet mask for a Class B IPv4 address is "255.255.0.0".   However, he may set it to whatever he wishes; hence "255.255.255.192".

The subnet mask determines which portion of the IPv4 address determines the network identifier.  The remaining portion determines the host id.

Logical "and" of IPv4 address:
     172.26.0.7          10101100.00011010.00000000.00000111
and subnet Mask:
     255.255.255.192  11111111.11111111.11111111.11000000 
leaves you with network id of:
     172.26.0.0          10101100.00011010.00000000.00000000

The above mask leaves six bits within the right hand octet to represent the host identifier portion of the IP address.  In this case, "0.0.0.7" or "7" from
"00000000.00000000.00000000.00000111".

2.  Ping "time=4ms".  This is the elapsed time from the transmission of each ping request to the receipt of each ping response in milliseconds (or something like that).  See http://en.wikipedia.org/wiki/Ping.

thank u for first question .i want to tell you that, earlier  time in the computer,when i ping to 172.6.0.1 -t.  then time =1097 ms, time=987ms.but now when ping to 172.26.0.1 -t  then time= 4ms,8=ms.in first case, is that sign the internet signal very high or surfing speed very first? and the second case, is the sign of slow internet signal or surfing speed very slow? plz tell me.

1.  Default Gateway.  The IP address 172.26.0.1 is identified in your first post as the default gateway.  This is the router that connects your local area network (LAN) to the outside world (or other local networks).

2.  Ping Response Time(s).  If you're pinging the default gateway from a local host "172.26.0.7", you're sampling the round-trip time between those two computers (host to gateway and back to host).

This traffic never reaches the internet, therefore is not directly affected by internet traffic that is outside of your LAN.  However, it is affected by the hardware, firmware, software, and number of components it must traverse to reach the default gateway; as well as the current processing loads on those components.  If other people on your LAN are using the internet, it will increase the processing load on the default gateway.  Because you're both competing for the services of the default gateway, this will increase your ping response times.

If anything, I would expect a higher ping response time as the amount of internet traffic passing through the default gateway increases, not the lower response time you seem to be reporting.

Higher ping times between your host and default gateway indicate more latency (delay) in your network which will affect your internet surfing experience.  But generally slow internet surfing is due to latency outside your LAN as the internet traffic attempts to navigate through multiple congested routers from overloaded web servers to reach you.

Something else that affects internet surfing is an overloaded Domain Name System (DNS) server that resolves Fully Qualified Domain Names (FQDN) to a numeric IP address (For example, resolving www.computerhope.com to 69.72.169.241).

To check latency outside of your LAN see the following:
     Tracert
     PathPing

I'm not sure which times you're reporting:
     o  Total time for all requests within ping session
     o  Actual Time of single request
     o  Minimum time of single request
     o  Maximum time of single request
     o  Average time of single request

The smaller the response time, the better (lower latency time).  Most people would consider a single request response time of 1097 ms (1097 milliseconds or 1.097 seconds) unacceptable.  Times of 4 or 8 milliseconds are much better than 1097 milliseconds.

It's all relative.  On my home network, with nothing between my host computer and default gateway except an ethernet cable (and no other host computers online); my normal ping request response time is 1 millisecond.

Edit Change(s):
1.  Corrected default gateway address from "172.168.0.1" to "172.26.0.1".
2.  Corrected local host address from "172.168.0.7" to "172.26.0.7".

thank u very much for this question. i configure  an internet connection in host computer,it have two LAN card ,first for internet connection(only they give me a RJ-45 cable which i attach in it for internet connection ).  and second is connect to switch.another 10 client computer attach to switch through RJ-45 cable.therefore i Share the internet connection from host computer.
there is the IP details from host computer:

ip address:172.26.0.7
subnet musk: 255.255.255.192
defult gateway:172.26.0.1
P DNS: not remembered
A DNS:    do
second LAN card
ip address:192.168.0.1
subnet musk:255.255.255.0
P DNS: left blank
A DNS: left blank

from ISP,they told me that when internet became slow down or not connect to internet ,then ping on 172.26.0.1 -t (which is defult gateway)for checkup.some day later i ping on it ,then ping show

Pinging 172.26.0.1 with 32 bytes of data:
reply from 172.26.0.1: bytes=32 time=1097ms ttl=255
reply from 172.26.0.1: bytes=32 time=776ms ttl=255
reply from 172.26.0.1: bytes=32 time=453ms ttl=255
reply from 172.26.0.1: bytes=32 time=1100ms ttl=255
reply from 172.26.0.1: bytes=32 time=997ms ttl=255
then i have no problem in connection or no slow surfing speed in host computer as well as client computer.

but now when i ping in 172.26.0.1 -t then it show

Pinging 172.26.0.1 with 32 bytes of data:

reply from 172.26.0.1: bytes=32 time=7ms ttl=255
reply from 172.26.0.1: bytes=32 time=6ms ttl=255
request time out.
request time out.
reply from 172.26.0.1: bytes=32 time=5ms ttl=255
request time out.
request time out.
request time out.
request time out.
reply from 172.26.0.1: bytes=32 time=11ms ttl=255
reply from 172.26.0.1: bytes=32 time=7ms ttl=255
 i have  problem for  slow surfing speed in host computer as well as client computer.
please tell me.

1.  Default Gateway.  It's not clear to me whether the "default gateway" is physically located within your office or at the ISP.  If at the ISP, then I think you're sharing it with other clients of the ISP.

I agree with your ISP that it's worthwhile to ping the default gateway (to check the round-trip response times) when you're experiencing difficulty with the internet; but in this case I can't coorelate your slow internet surfing with the ping response times you've provided.  I suggest you look elsewhere for the problem.

2.  DNS Server.  Suggest you ping the DNS Server address(es), the next time you experience difficulty (slowness) surfing the internet.  If the DNS server is down or overloaded, you'll have difficulty resolving Fully Qualified Domain Names (FQDN) of websites to their numeric IP address.  Your Internet browser (e.g. Internet Explorer, Mozilla Firefox, Opera) needs the numeric IP address to connect. 

While internet surfing is good, you should ping the DNS server address(es) to get a baseline of the response time.  This can then be compared to the response time when surfing is slow.  Note:  It's possible the DNS server is configured to not respond to a ping request to reduce possibility for "Denial of Service" attacks.

You may also manually configure your host Internet Connection Sharing (ICS) computer to use a different set of DNS server addresses.  It's possible your ISP isn't providing enough DNS servers or ones that are powerful enough to keep up with the demands for service.  If you do an internet search, you may find alternative "open" DNS servers that you could try.  Your host ICS computer should be configured with at least two DNS server addresses.

3.  Website Address(es).  Record the numeric IP address(es) for a couple of websites you use.  When you're having difficulty accessing the site by its domain name, use the numeric address instead.  If the numeric address works well, then you've isolated the problem to domain name resolution.  Numeric addresses may be used with ping utility as well as internet browsers.

You may also use ping, pathping, and tracert utilities to measure connectivity and round-trip response times to the website.  This might be more useful than pinging the default gateway.  Again, note that some websites might be configured to not respond to ping requests to reduce exposure to "Denial of Service" attacks.  So find out which ones will respond before you experience issues (for a baseline).

4.  Office Configuration.  I wonder whether your ICS host computer can handle the internet access demands your ten client computers place upon it.  If the host computer is experiencing slow internet access, disconnect LAN side cable to see whether the client throughput processing is slowing it down.