WAN Acceleration takes Center Stage

Continued from page: 1

Thursday, November 02, 2006

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Choosing a thin client
Before going for the thin client solution, you should first analyze the need for it. You need to consider the following parameters before choosing a thin client:

1. Whether you are using dumb terminals for accessing existing legacy applications and need more power and flexibility for users?
2. If you have multiple offices in remote geographical locations and you want to share your central IT resources.
3. You have multiple applications running on multiple platforms and you want to give access to all these to your employees, sales partner, etc from a single device.
4. You have highly sensitive data on your centralized datacenter and you don't want to create copies of it on the user's desktop, while still giving them access.
5. You have interconnected your central and satellite offices and are using applications on a client-server architecture. Unfortunately, you have to do frequent updates on application software at central and/or satellite offices due to process change.
6. If you have distributed applications and data over a network
7. A limited IT staff compared to huge IT resources or if you want to offer end-user application support remotely.

Types of thin clients
Thin client devices are categorized in four categories-Basic, Robust, PXE and Mobile.

Basic The basic thin client device has features like RDP, ICA and optional terminal emulation. It lets you access basic remote terminal services and applications from Windows or UNIX servers. You can run multi-user Windows on a centrally managed server using either the Citrix ICA or the Microsoft RDP protocol to remotely display on a user's desktop, the application running on the server. This is quite cheap and provides an excellent performance. It does not require any additional connectors like USB.

Robust These devices have some advanced features as compared to basic thin clients. They give you features like RDP, ICA, terminal emulation and a built-in browser. Plus, they also have ability to attach external devices such as a printer and USB storage.

Nowadays we have Robust thin clients coming with built-in sound card, that allow users to stream audio files on their end. They have a built-in Web browser, which lets users to run Web applications without placing any extra burden on their servers. Because Robust thin clients support Citrix NFuse and legacy dumb terminal emulations, they offer users access to basic HTML pages and replace terminal screen.

PXE It converts your existing desktop PC to thin client devices. You just need to add PXE network cards on all desktops. These desktops get booted remotely from the remote boot server instead of local hard disks and get converted into basic thin clients. You can use RDP, ICA or X terminal from them.

So, if you have old desktops lying around, you can convert them into thin clients and use them. You can use LTSP (Linux Terminal Services Project) for this.

Mobiles & thin clients
Now-a-days you can access your corporate applications using you mobile devices. PDAs and mobile phones are coming with thin client plug-ins, which enable users to access corporate servers remotely when they are on move. PDAs running Windows CE can use Window Terminal Client or VNC to access Windows Terminal services, VNC server, etc. Idokorro Mobile Desktop is a client for Windows Terminal Services, Remote Desktop and Virtual Network Computing (VNC) for Smartphone devices and BlackBerry. For more details checkout http://remotedesktop. qarchive.org/downloads. html.

With PCQLinux 2006, we have created a new install option for implementing terminal services on PCQLinux. For this we have used latest LTSP (Linux Terminal Service Project). This is beneficial for those organizations that want to outsource their business processes and want BPOs to access their datacenters over thin client infrastructure.

On the client side LTSP requires a minimum of Pentium I with 64 MB and PXE (Pre boot- eXecutable Environment) LAN interface. It does not require any hard disk on the client machine, because it boots the thin client from the LTSP server. This saves lot of cost as well. We recommend using identical hardware on all your nodes if possible. This will make your life much easier when configuring for drivers.

HP Compaq t5720 Thin Client
This thin client from HP comes in the category of Robust thin clients, because it also has an Internet Explorer browser. You can use this device to access RDP and ICA terminal client solutions. Plus, if you are not using any of the above mentioned terminal services in your office, then also you can use this to access Web-based applications using its browser. The thin client has a heart of AMD Geode NX 1500 1.0 GHz processor, 256 MB RAM and SiS741GX Integrated/UMA graphics with 16 MB shared graphics memory. It also has built-in audio, 6 USB, one serial and parallel port. The device runs on Windows XP Embedded. In addition, you don't have to configure anything for the connections; it's simply a plug and play device. The OS resides on 512 MB flash memory that can be expanded as per user requirements. We have tested this device with both Windows Terminal server and Citrix Presentation server and tried to access both full desktop and individual applications hosted on Citrix. The experience was seamless. We did not have to do any configuration for connecting to the terminal services. However, other thin clients that we have create connections separately. We also checked the audio quality of the devices, by accessing streaming music files from the media player application hosted on Citrix; the quality was pretty decent.
	Price: Rs 22,000 (1 yr warranty) Key Specs: AMD Geode NX 1500 1 GHz, SiS741GX Integrated/UMA graphics Contact: HP India, Gurgaon Tel: 9312666760 E-mail: durai-m.singh@hp.com

Installing from PCQ Linux 2006
Boot a server class machine from the PCQLinux 2006 CD #1 and start the installation process. Now from the install options select the 'Server' option and select the 'Terminal Server' option from the Server options screen. Press next to setup PCQ Linux 2006 server with terminal services. Before starting the installation, PCQLinux installer will show you the package that you have selected, here from the package selection list select Network services, Legacy Network and Gnome and KDE desktop environment with KDE and GNOME development. Once you are through with the installation, boot the machine in to GUI and login as root. Make sure, the server on which you are configuring Terminal Services is connected to Internet. Now, on the GUI console, open a terminal window and on the terminal console type-in 'ltpsadmin.' This will open a command line interface for you. Here, select 'Install/Upgrade packages.' It will directly connect your machine to the Linux Terminal Server Project's site and download the latest packages for you. Then installer will also ask you for the install path; type '/opt/ltsp' and press Enter. When prompted, select additional packages from the list shown pressing 'A' and then 'Q'. Press Enter to confirm. The packages will be downloaded and installed.
After completing downloads, select 'Configure LTSP' from the installer and press Enter. Here, you will be shown eleven options, one for each service. Select all the services one by one and enable them by pressing Enter. It will automatically configure the selected services.

DHCP server with PXE Boot 
Now, you have to configure the DHCP server on PCQLinux 2006, the diskless clients for IP address assignments. For this edit /etc/dhcpd.conf and add the following lines as shown below:

ddns-update-style none;
default-lease-time 21600;
max-lease-time 21600;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.3.255;
option routers 192.168.3.1; #<-- Router or Gateway IP
option domain-name-servers 192.168.3.38; #<-- LTSP Server IP
option domain-name "ltsp.pcquest.local"; # <--domain name
option root-path "192.168.3.38:/opt/ltsp/i386";
#<-- NFS Share
option option-128 code 128 = string;
option option-129 code 129 = text;
subnet 192.168.3.0 netmask 255.255.255.0 {
range dynamic-bootp 192.168.3.80 192.168.3.253; # <-- DHCP IP Range
filename "/lts/2.4.26-ltsp-3/pxelinux.0";
#<- Boot image File
}

Restart the DHCP server.
# service dhcpd start

Wyse S10 Thin Client

It's a small, cool looking device and takes very little space. It is also simple to install and use. The device is plug 'n' play and its thin client OS comes with integrated support for RDP and ICA sessions. All connections can be easily customized through its connection manager. It also provides support for Citrix WinFrame, MetaFrame, and Presentation Server .The device uses an AMD Geode GX 533 clocked at 400MHz and has four USB ports, one 10/100Base-T fast Ethernet port, one serial port, an audio in/audio out and a built-in Kensington slot. The product we got came with a PS/2 mouse but we were not able to find a PS/2 port on the device, although its manual claims it ships with a PS/2 mouse. However, you can use a USB mouse with it. The device has no fans or disks, comes with 32 MB RAM and no data can be stored on the thin client including the configurations. This provides data security and integrity. This thin client also supports Image loading via DHCP and FTP. Wyse also provides a thin computing software called Wyse Streaming Manager which can stream operating systems and applications from a server to thin clients as and when required by the user. This provides users with a PC like feel and all data is stored on the server thus providing data integration. According to Wyse all data transmitted during this time is encrypted.

Configuring clients
Now edit /opt/ltsp/i386/etc/ lts.conf file, and confirm the entries are as given below:

[Default]
SERVER = 192.168.3.38 (IP address of PCQLinux machine running Terminal service)
XSERVER = auto (Xserver driver for client machine)

X_MOUSE_PROTOCOL = "PS/2"
X_MOUSE_DEVICE = "/dev/psaux"
X_MOUSE_RESOLUTION = 400
X_MOUSE_BUTTONS = 3
USE_XFS = N
RUNLEVEL = 5
X_MODE_0 = 800x600
SCREEN_01 = startx

After this, issue the following commands:

# chown root:root /opt/ltsp/i386/etc/build_x3_cfg
# chmod 0755 /opt/ltsp/i386/etc/build_x3_cfg

In our above configuration, the XSERVER parameter contains the value 'Auto', because we were using clients having different sets of display. Next step is to enable GDM services on the terminal server, so that it can serve the GUI to the client. In order to do so, open /etc/X11/gdm/gdm.conf file and scroll down to [xdmcp] entry and change the following entry as mentioned below:

Enable=true
HonorIndirect= true
MaxPending?= 4
MaxPendingIndirect?= 4
MaxSessions= 16
MaxWait?= 15
MaxWaitIndirect?= 15
DisplaysPerHost= 2
PingIntervalSeconds= 15
Port=177
Willing=/etc/X11/gdm/Xwilling

Save these entries in the gmd.conf and then issue the following commands:

# gdm-safe-restart
# service xfs restart

GIGABYTE Ultra Slim Thin Client
This is a hardware based thin client from GIGABYTE. It comes in a small form factor. The heart of the device is a VIA C7 1.0 GHz processor with 1 GB DDR RAM housed on GA-C7V7-ASI-RH-GB1 motherboard. It also has a built-in sound card and 10/100 Mbps LAN card. For display it has VIA UniChrome Pro + MPEG-2 decoder onboard graphics that connect to your monitor. In addition, it has 4xUSB ports for connecting additional USB devices such as USB printer and storage. It has one LPT and COM port. It's a plug and play thin client and very easy to setup. The device runs a stripped down version of Linux and gives a GUI interface once it is booted. On its desktop it shows two tools. One is used to configure the device network, mouse and keyboard settings, adding NFS and SMB shares setting, etc. The other is used to make new thin client connections to the host server. It also has a search button that searches the terminal services host running on the network. This helps users to select the hosted terminal server that they want to connect with. It supports all the terminal services like Microsoft Terminal services (RDP), VNC, Citrix, X11, Shell script and many more.
	Price: Rs 9,000 (1 yr warranty) Key Specs: VIA C7 1.0 GHz processor, 1 GB DDR RAM, 4 USB ports, onboard sound and LAN Contact: Gigabyte Technology, Mumbai Tel: 26526696 E-mail: sales@gigabyte.in

With this, your LTSP server is ready to serve the diskless nodes. Connect the diskless nodes to the network and boot them from their PXP LAN card. And in few seconds you will get a GUI login screen on the nodes.

Give the user name and password to login and you will get default Gnome interface on the nodes.

Windows 2003 for diskless clients
To configure PCQLinux2006 for serving Windows clients, just open /opt/ltsp/i386/etc/lts.conf file, and add or change the entries as given below:

RDP_SERVER = 192.168.3.29 #(Windows Terminal Server)
RUNLEVEL = 7
X_COLOR_DEPTH = 15
SCREEN_01 = rdesktop

Server is a central deployment and thin client management solution. It happens to be vendor independent software, i.e. at client side you can use any thin client or you can convert your old computers into a thin client.

It can distribute OS to thin clients from a central location and manage the thin client and sessions through web management console. All thin client devices and users connection settings can also be managed via its web management interface. It shows currently active thin clients and user sessions, generates reports and includes a centralized database of thin client Syslog events.

At the client side 2X uses a small linux operating system as a ThinClient OS. The 2X ThinClient OS itself can be retrieved from the TFTP server via PXE or Etherboot, or it can be booted from a storage device or you can just boot it through a CD-ROM as a live CD.

Using the LTSP Admin Tool you can watch all the required services that are needed for LTSP

All connection settings are stored on the management console and upon boot-up, thin clients connect to the server and retrieve the settings that will determine how and which terminal server they will connect.

Settings can be applied to an individual thin client (by MAC address), by username, by group (effectively capturing all the members of the group), or by organizational unit (OU). The Server software can run on Windows as well as on Linux.

Deploying 2X
Installing 2X ThinClient Server is simple, once the server is installed launch it. First it will ask you to create a administrative account. Once it has been created you can login to 2X's console with it.

When you login for the first time, it will ask you to configure the connections and provide the 2X ThinClient OS image. Here click on configure connection button, a new window will open. Here provide a name for the connection and choose which protocol you want to use.

By default 2X supports its own 2X published applications, Citrix published applications, ICA and windows RDP protocol. You can also change a protocols default settings if you want. To do this click on Add Protocol button, a new window will open here provide a name for new protocol and specify is type i.e. RDP or ICA etc.

In 2X ThinClient Server, you can customize default protocol settings and choose what kind of encryption, bandwidth, services, display, etc to use

Now specify settings like how much bandwidth should be used by the protocol, you can also enable or disable the encryption and you can also customize the display settings. Now click on Users tab to choose which users will be logging on from clients, here you can either choose the users from windows active directory or create local users for 2X.

Once you have added the users and specified the protocol to use, last basic configuration is left to specify the 2X ThinClient OS image. To do this you need download 2XThinClient OS image from their website. If you plan to boot your thin clients through CD, just burn the image and boot your ThinClients with it. If you plan to use 2XThinClient's inbuilt TFTP server, from its main console choose ThinClientOS under Thin Clients menu.
In the new window click on Browse button and provide the path of the downloaded 2XThinClient image. Now you can boot your thin clients with PXE boot option and they will automatically boot through 2XThinClient OS.

After the 2X ThinClientOS has booted, it obtains its connection settings from the 2X ThinClientServer. These settings are then used to connect to the terminal server. After 2X ThinClientOS has booted, it obtains the IP address of 2X ThinClientServer from the network settings returned by the DHCP server.

Once the clients have connected to the server, you can login back into the 2X management console to manage the thincleint and sessions.
In main console the 'Sessions' node shows you the users that are or have connected to a terminal server. There are 3 sub-nodes for currently active sessions, past sessions and erroneous sessions.

To manage a thin client, click on the 'Manage' node under 'Thin Clients'. All thin clients will be listed in the right pane. Here you can manage things like Hostname, Printer to be used, input devices, display settings, logging etc.

Deploying Citrix MetaFrame Presentation Server
This is an application virtualization solution from Citrix, available on all major platforms. It allows users to access applications, central business resources or full desktops remotely from the servers. Administrators can manage everything centrally. We implemented Citrix Presentation Server on a Windows 2003 Server. Before deploying it, you require ASP.NET 1.1 and the latest Javaruntime installed. Configuring IIS with ASP Open the Manage Server console from Administrative tools and add the Application Server role. This will automatically install IIS and configure ASP.NET. Citrix MetaFrame Presentation Server Now, from Citrix CD pack. Install Citrix License Server, Citrix MetaFrame Presentation Server and its components, and management console in that order. Once all the components are installed. You need to reboot the machine once and Citrix Presentation Server is ready to host your application for thin client users. Publishing applications In order to publish application on Citrix MetaFrame Presentation Server. Open Citrix Meta console from Start>Programs>Citrix>Management Console. This will open an interface as shown in the screen shot. Here on left panel you can set the various options like application publishing, users policies, deploying applications on the server depending on the users needs. Let's see how you can publish application on the Presentation server. From the left panel select the Application option and right-click on it. From the context menu select 'Publish New Application.' This will take you through the wizard to create an application profile that you want to publish. The wizard will ask you the name of the application, description and the location of the application and working directory of the application. You also need to set up screen resolution and color settings for the application you are publishing. Finally add the presentation sever name and user permission to host the application and finish the wizard. With this the application gets published. Using published applications Configure the thin client with ICA protocol and also give the IP address of the presentation server. The thin client also lets you search for the published applications. Select the application that you want to access from the thin client and connect to the remote presentation server. Once connected, you will be authenticated and the selected published application would be served at the thin client. It can also be accessed from the thick client running Citrix client component called 'Citrix Program Neighborhood.'
	Citrix MetaFrame Access Suite lets you monitor entire server farms from a single console. This includes network security, alerts, etc

Anil Chopra, Anindya Roy, Anubhav Verma, Sanjay Majumder, Swapnil Arora and Vijay Chauhan

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