从源辞典

I use azureus as a bt client to download files. But noticed that the upload bandwidth usage reported is not correct.

For example, if the shown bandwidth usage is as follows.

UP: 6KB/S
DOWN: 26KB/S

Actual usage:
UP: 11KB/S
DOWN: 34KB/S

It shows the difference is about 5KB/S.

今天发现是Starhub的限制不能用NTP (network time)。

由于我安装了OpenWrt，我就想到用tcpdump来看一下究竟是为什么NTP不可以用。

我这边router本身的IP 是218.186.146.114，time.nist.gov是192.43.244.18

原来在Windows XP下，当点击”Update Now”，XP会用123这个端口作为自己的发送端口。因为Starhub限制incoming port 123，所以这个package就不可能回来了。
22:40:53.787956 IP 218.186.146.114.123 > 192.43.244.18.123: [udp sum ok] NTPv3 sym_act, strat 0, poll 8, prec -6 dist 0.000000, disp 1.015625, ref (unspec)@0.000000000 orig 0.000000000 rec 0.000000000 xmt 3340708897.968750000 (2005/11/11 22:41:37)

而我发现Grandstream IP phone居然可以用NTP，原因是它本身的发送端口是一个随机的端口如9876，所以这个package就可以回来。

22:41:34.163537 IP 218.186.146.114.9876 > 192.43.244.18.123: [udp sum ok] NTPv4 client, strat 0, poll 4, prec -6 dist 1.000000, disp 1.000000, ref (unspec)@0.000000000 orig 0.000000000 rec 0.000000000 xmt 0.000003515
22:41:34.469887 IP 192.43.244.18.123 > 218.186.146.114.9876: [udp sum ok] NTPv4 server, strat 1, poll 4, prec -17 dist 0.000000, disp 0.000000, ref ACTS@3340708873.390592008 (2005/11/11 22:41:13) orig 0.000003515 rec -954258402.130201518 xmt -954258402.130181521

最近不知怎么的，打开一个网页的时间稍微长点就转到一个叫做Accoona的搜索引擎上了。

烦死了。

我一向很小心的，怎么也在不知不觉中装了这个软件。用Hijackthis扫描了一下，果然有它 的踪影

O2 - BHO: Accoona Search Assistant - {944864A5-3916-46E2-96A9-A2E84F3F1208} - C:\Program Files\Accoona\ASearchAssist.dll

讨厌的spyware。删无赦

Tried to search for my blog name 从源杂谈 using MSN, Yahoo, and Google.

I noticed that Google does not have my sited included. While MSN and Yahoo do have my blog listed.

Google is no longer good in search engine.

前些日子给公司做了个DNS服务器。服务器是Redhat Enterprise Linux ES 操作系统。在我的建议下，买了个hosting software: Ensim Pro。

先说一下这个服务器的配置吧。
Thermaltalk Kandalf VA9000 Tower Casing (S$300+)
Antec 550W PSU (S$200+)
Dual Xeon 3.0G 800M FSB
Supermicro X6DA8G2 MB
4 x 2G DDR RAM
2 x 36G Seagate 10K RPM SCSI HDD (S$700+)

全部是我自己组装的，呵呵。算是长经验吧。跟装一般的PC没什么区别，就是装主板有点麻烦。幸亏这个机箱支持双CPU，CPU散热器是直接固定在机箱上的。

电源也是适合服务器的，因为主板特别说明要单独的12V输出。

The server pauses for every file uploaded.

Server software: Proftpd

Rosolved:

Edit proftpd.conf file:
vi /etc/proftpd.conf

Add the following lines after default server:
UseReverseDNS off
IdentLookups off

Restart proftpd:
service proftpd restart

Linksys这款Router有很多第三方的Firmware。无非是为了更多的功能，如QoS, Wi-Fi Boost等功能。官方的Firmware也已经有了QoS的功能了，只是比较简单，现在我们来看一下这个QoS是否真的起作用。

我的是V2.2版本的，到linksys网站下载了最新的FW, V4.20.6

QoS的主要应用是给我的IP phone保障通话质量的。IP Phone 为Grandstream BT101，用的是FWD的服务。

先看一下QoS设置截图

QoS设置为Auto。

顺便提一下我用的带宽是up/down=256k/2Mbps
IP phone 的codec(G7211.u/PCMU) 所需要的带宽约为80kbps

然后分别试了拨打613 echo test号码的效果。

1.未用IP电话

up/down=232k/1668kbps

2.用IP电话拨打613通话中

由此可见，Auto QoS是起作用的，保证了IP Phone的带宽

up/down=152k/1635kbps

1. Check current UID
nireport . /users name uid

2. Add a user
echo ‘henry::512:512::0:0:Henry James:/Users/henry:/bin/bash’
| sudo niload -v passwd /

3. Change password
sudo passwd henry

再跟大家说说使用这个网络电话的心得。

其实不用硬件电话(Hardware Phone)，一样是可以达到同样的通话效果。用硬件电话的好处就是不依赖电脑。来电话了不用手忙脚乱的找耳机麦克风。。。

试过了两个软电话(Software Phone)，X-Lite和pulver.Communicator。他们都支持通用的Codec，如：PCMU(G.711U), PCMA(G.711A), G723, GSM等。其中G.711可以提供较好的通话效果。

用过这两个软件后，发觉pulver.Communicator （以下简称pC）好用。

1. 通话效果好过X-Lite (用X-Lite可以明显感觉到断断续续的声音，而用pC就跟用硬件电话差不多）
2. pC容易与FWD使用（因为pC本身就是为FWD所特设的，根本不需要自己设置什么。而X-Lite要自己设置Network Settings）

硬件电话目前只用过一个Grandstream BT101。物美价廉。。。呵呵。在eBay上USD60就可以买到。

另外说一下用软电话跟硬电话兼容的问题。开始的时候的确有个问题：就是用Grandstream打过来的，用pC接听，Grandstream方可以听到，但是pC方听不到对方。这就是所谓的one-way audio问题。后来发觉是pC软件里的一个设定：DTMF sent when initiating an audio call。默认设定是 “7″。在这个默认设定下，对方会听到Beep一声。把它改成”Tweak Microphone”就解决了one-way audio问题。

DATE : 30th June 2005, Thursday

TIME : 9.00 am -12.00 pm
Registration commences
at 8.30 am

VENUE : M Hotel Singapore
81 Anson Road
Singapore 079908

RSVP : Kindly RSVP before
23 June 2005
Via Web : Click here
Via Phone : Ms Sarah Anne Pinto
Telephone: 6723 3828

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