Improve throughput with Intel 5100 in wireless N mode

When I test its throughput (from a wired computer) in wireless N-only mode with iperf in vista, the maximum throughput I was able to get is around 25Mbits/s although it shows 270-300Mbps data rate by windows. The router is a Airlink AR670W with stock firmware 1.01 and 40MHz channel width/Auto(DFS) channel. It's not faster than the throughput of Wireless G mode.

After I update the firmware of AR670W to DD-WRT build 13069, I found the signal quality of the Intel 5100 client is only around 23% at full Tx power (251mW) from the wireless status page. And it can only improves the throughput to ~35Mbits/s with iperf -w 64k -c intel-5100. Then I started to adjust the following things:

1. Orientation of the two antennas of AR670W: On one position I found the signal quality of Intel 5100 was improved to 34%. 
2. Manually set the channel number: After doing a site survey, I found the least crowded channel was not the one being picked up by DD-WRT. So I changed the channel number and the signal quality of Intel 5100 was improved to 40%
   
   Then I tested the throughput again, and no surprise it's now ~80Mbits/s. Even if I further increase the TCP windows size of iperf from 64k to 10M or reduce the Tx power to half (126mW), the throughput remains at ~80Mbits/s (wired to wireless). Later I had to enable the N-only wireless mode on a D-link DIR-655 router to maximize the throughput of another Intel 5100.

Samsung SGH-A887 (solstice)

1. QUALCOM USB mode of Samsung 3G phones:
   
   
   
   • Dial *#782872# and confirm after 2 seconds to activate the mode
   • Connect phone to PC USB port with USB cable
   • After the drivers are installed, the following two were found under Ports: 
   • PHD HS-USB diagnostics 9002
     
   • PHD HS-USB NMEA 9002
   • PHD HS-USB Modem 9002 was installed under Modems
   • Two USB Composite Devices were installed under Universal Serial Bus Controllers
   • To exit QUALCOM mode, dial *#726872# and confirm after 2 seconds
   
   
   
2. Firmware downloader mode:
   
   
   
   
   • Power off the phone
     
   • Remove any memory card you may have and then remove the SIM card
   • Hold down the 'Volume down' key (The bottom rocker button on the left side of your phone) and the camera button and press the power on button. 
   • A887 should start up into a screen with these on the top: DEMSBL BOOT loader for MSM6290 More than Downloader V5.43
   • Get MultiLoader V5.56 here to download the firmware for MSM6290
     
   
   
   
   
   
   
   
   
   
   

Asterisk (PBX) and PAP2T

1. hasexten=yes|no
   If the context for a peer sets hasexten=yes, Asterisk creates a hint for the user in the default context as shown below for a SIP peer 6000.
   CLI> dialplan show default
[ Context 'default' created by 'pbx_config' ]
'6000' => hint: SIP/6000 [pbx_config]
1. Dial(${HINT}) [pbx_config]
   Therefore I can use Goto(default,6000,1) to ring it
2. [general] user in users.conf
   It's set the default contexts for all other users. They can be overridden though. The following are in my [general] user (all my users are using SIP):
   fullname = My Name
;
; Starting point of allocation of extensions
;
userbase = 6000
;
; Create SIP Peer
;
hassip = yes
;
; Create IAX friend
;
hasiax = no
registeriax = no
;
; Create manager entry
;
hasmanager = no
callwaiting = yes
threewaycalling = yes
callwaitingcallerid = yes
transfer = yes
canpark = yes
cancallforward = yes
callreturn = yes
call-limit = 100
qualify = yes
disallow = all
allow = ulaw,alaw
type = friend

3. Asterisk directed call pickup
   I have two extensions: 6000 and 8888. Typically when there's a incoming call, only extension 6000 rings. I can pick up the call from the other extension though by pressing the # key from extension 8888. Therefore I have the following in features.conf
   [general]
pickupexten = #
   and the following in extensions.conf:
   [globals]
voipbuster = SIP/voipbuster

[CallingRule_pickup]
exten = _#,1,Pickup(6000@default)
exten = _#,n,Hangup()

[DLPN_8888]
include = CallingRule_pickup
include = CallingRule_VBOut
include = default

[CallingRule_VBOut]
exten => _001.,1,Dial(Local/${EXTEN:2}@gv-outbound/n)
exten => _00[2-9]X.,1,Macro(trunkdial-failover-0.3,${voipbuster}/${EXTEN:0},,voipbuster,)
   I had to add the following to the Dial Plan of the line that will pickup the call in my PAP2T to pass # key directly to Asterisk: #S0
   
4. Blind transfer
   I use the * key for Blind transfer. Therefore I have the following in features.conf
   [featuremap]
   blindxfer = *
   and the following in extensions.conf:
   [globals]
DIALOPTIONS = tT

[DLPN_6000]
include = CallingRule_VBOut
include = default
include = parkedcalls
include = conferences
include = ringgroups
include = voicemenus
include = queues
include = voicemailgroups
include = directory
include = pagegroups
include = page_an_extension
exten = _*,1,Transfer(8888)
   I had to add the following to the Dial Plan of the line that will initiate the transfer in my PAP2T to pass * key directly to Asterisk: *S0
5. Connecting PAP2T to the telephone lines 1&2 in my house (T568A type socket): I cut one standard 2-wire RJ11 telephone cable assembly in half and connected them to Blue and Orange lines of the T568A. That will enable me to connect a phone onto the wall outlet at any room to my PAP2T.