Slow/fail connections dLink DI-624

Product : Wireless Access Point dLink.
Part Involved : DI-624 or DI-624+.
Summary : Recomendation to set up configuration of Access Point.
Scenario : Sometimes the device does not respond or is very slowly
Company : National Institute of Cancer sickness of Peru (INEN).
Reference Date : June 2006.

First the equipment was bought to supply the need of LAN data ports of structured cabling then it was very attractive the idea to replace that set of LAN data ports with wireless connections. One of the LAN data port of the equipment is connected to the floor distribution of the structured cabling while the SSID and additional parameters were set up, upto here there is no problems; I added a log trace of the activities did by the Access Point dLink DI-624 when is working connected to some type of LAN structure with 600 computers. Take as reference that the next log was collected some saturday afternoon -very low traffic data-

.16:14:23.506164 00:a0:f8:ae:9b:44 (oui Unknown) > 01:a0:f8:f0:f0:02 (oui Unknown), ethertype Unknown (0x8781), length 237:
0x0000: 002d 0000 00d7 0000 0007 0007 0000 0001 .-..............
0x0010: c0a8 47d4 0000 0000 0000 0001 0000 0e02 ..G.............
0x0020: 0300 0000 0000 0000 4e45 4f50 4c41 5349 ........NEOPLASI
0x0030: 4341 5300 0000 0000 0000 0000 0000 0000 CAS.............
0x0040: 0000 0000 0000 0000 0000 0000 000c 3033 ..............03
0x0050: 2e37 .7
16:14:23.883708 IP COMPUTO003.137 > 192.168.71.255.137: UDP, length 50
16:14:24.226375 arp who-has COMPUTO003 tell NETWORKING01
16:14:24.226530 arp reply COMPUTO003 is-at 00:05:5d:6b:11:5b (oui Unknown)
16:14:24.226536 IP NETWORKING01.137 > COMPUTO003.137: UDP, length 50
16:14:24.226752 IP COMPUTO003.137 > NETWORKING01.137: UDP, length 229
16:14:24.307070 arp who-has 192.168.71.136 tell FILESERVER
16:14:24.633673 IP COMPUTO003.137 > 192.168.71.255.137: UDP, length 50
16:14:25.239559 arp who-has 192.168.71.136 tell NETWORKING01
16:14:25.533321 IP 192.168.0.12.1900 > 239.255.255.250.1900: UDP, length 253
16:14:25.533488 IP 192.168.0.12.1900 > 239.255.255.250.1900: UDP, length 253
16:14:25.533597 IP 192.168.0.12.1900 > 239.255.255.250.1900: UDP, length 271
16:14:25.533773 IP 192.168.0.12.1900 > 239.255.255.250.1900: UDP, length 271
......
.....
.....
16:14:31.015531 IP 192.168.0.11.1900 > 239.255.255.250.1900: UDP, length 317
16:14:31.020414 IP 192.168.0.11.1900 > 239.255.255.250.1900: UDP, length 245
16:14:31.024321 IP 192.168.0.11.1900 > 239.255.255.250.1900: UDP, length 319
16:14:31.036038 IP 192.168.0.11.1900 > 239.255.255.250.1900: UDP, length 289
16:14:31.043850 IP 192.168.0.11.1900 > 239.255.255.250.1900: UDP, length 313
16:14:31.547790 IP LOGIS04.138 > 192.168.71.255.138: UDP, length 201
16:14:34.447520 IP PISO701X.137 > 192.168.71.255.137: UDP, length 50
16:14:34.458966 arp who-has 192.168.71.137 tell FILESERVER
16:14:38.743974 IP NETWORKING01.137 > FILESERVER.137: UDP, length 50
16:14:38.750300 IP NETWORKING01.137 > 239.255.255.250.137: UDP, length 50

And after review log information I found the confirmation of the ip assigned to Access Point (192.168.0.11) and comparing between 16:14:25.533321 and 16:14:31.043850 (6 seconds) there are 4,298 request executed by Access point through port 1900 to access internet causing a excessive broadcast into LAN, forcing to the rest of devices connected to LAN to wait pass this 6 seconds, this cycle -set of request petitions through port 1900-is repeating constantly and I identify that this process slows the conecction of all the devices into LAN. The default values of this type of equipment considers enable this feature then proceed with the next window to disabled that option and in consequence enhanced the speed of the connections into LAN when you are using this type of equipment. UPNP functionality is associated with por 1900.