how long is the delay to renew IP address (802.11b adapter)?

  • Thread starter Thread starter Eric
  • Start date Start date
E

Eric

Hi,

I am working on a project on PPC 2003. In this project, I need to set SSID
and then release/renew IP address so the PPC can connect to an AP or a
desktop.

Now I found the following phenomenon:

1. when I turn WZC (wireless zero config)off, the machine will obtain IP
address around 16~17 seconds after I set SSID and release/renew IP address
by calling IpReleaseAddress/IpRenewAddress;
2. when I turn WZC on, the machine experiences the same delay, but Setting
SSID does not work.

So, I am wondering whether such a delay is normal? If not, I might got
something wrong...

Thanks,

Eric
 
For Pocket PC, I believe it depends on the device you are using. Some Wifi
models seems to work faster than others. These are observations about using
the device, getting IP or connecting to access points, etc but not with
using the WZC apis.

David
 
Eric,

16-17 seconds sounds quite bad

Depending on your WLAN configuration (e.g. 802.1X authentication or not) it
may take some time between associating with the AP and being able to send a
DHCP request.

What may happen is that the first request the DHCP client sends gets lost,
and only a retransmission gets through. You may be able to verify this by
checking the 'secs' field in the DHCP DISCOVER that eventually arrives at
the DHCP server

Another way to test this, could be to insert a sleep() after setting the
SSID but before doing the release/renew sequence. Perhaps release / setSSID
/ renew would be a better sequence, since normally the client has obtained a
lease on the network it is currently connected to.

Also, the DHCP client may wait some time before sending a DHCP REQUEST based
on an offer it received. This time can probably be tweaked
 
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