Showing posts with label Security. Show all posts
Showing posts with label Security. Show all posts

Wednesday, November 5, 2008

Sierra Wireless AirCard 875


Sierra Wireless AirCard 875 menghubungkan PC dan Mac seri lama ke jaringan HSDPA dari berbagai jaringan seluler berkecepatan tinggi yang saat ini berlomba-lomba menyediakan layanan tersebut. Meskipun demikian, peruntukan kartu jaringan nirkabel ini tentu utamanya untuk mendukung kebutuhan koneksi internet dengan mobilitas tinggi. Kemanapun dan dimanapun pemakai laptop berada, ia dapat menikmati internet selama di area tersebut mendapatkan sinyal yang cukup dari penyedia jaringan HSDPA yang digunakan.

Desain

AirCard 875 secara desain cukup baik. Dengan kombinasai warna hitam dan oranye yang merupakan ‘titipan’ Cingular karena AirCard 875 memang bekerja sama dan Cingular dan oleh karena itu terdapat logo Cingular pada bagian permukaan. Lampu LED berwarna biru mengindikasi kondisi aktif kartu tersebut, informsi 2G EDGE dan 3G HSDPA yang aktif, juga informasi jangkauan jelajah yang tersedia.

Setup

Sierra AirCard 875 tidak memerlukan proses instalasi yang rumit. Anda hanya perlu memasangnya pada laptop Anda, kemudian jalankan Connection Manager Software yang disertakan. Sama sekali tidak ada kesulitan pada pemakaian pertama.

Kinerja

Spesifikasi HSDPA saat ini memungkinkan kecepatan sebesar 3,6Mbps downstream dan 384Kbps upstream. Cukup kencang meskipun pada kenyataannya nanti tentu kecepatan ini tergantung load jaringan pada saat itu.

Ketika membandingkan AirCard 875 dengan AirCard 875U USB dan Option GT Max HSDPA pada Windows XP dan Vista, kami menemukan kinerja AirCard 875 menunjukkan kecepatan yang sangat baik. Hanya saja, data rates AirCard 875 sedikit lebih lambat dibanding 2 lainnya. Pada ujicoba perbandingan ketiga kartu modem wireless yang kami lakukan, kecepatan download yang ditunjukkan AirCard 875 rata-rata sebesar 878 Kbps dengan kecepatan puncak 1,51 Mbps, sementara kecepatan upload sebesar 284 Kbps.

Pada kedua modem lainnya, kecepatan download rata-rata berkisar pada angka 350 Kbps. Latency pada kedua kartu pembanding juga sangat mirip. Sehingga dapat dikatakan kinerja kedua modem tersebut hampir sama. Namun demikian, salah satu dari 2 modem tersebut mengalahkan AirCard 875 pada 30 ujicoba download dari 36 ujicoba yang dilakukan. Untuk hal ini, AirCard 875 menunjukkan tingkat penerimaan yang kurang lebih sama dengan AirCard 875U USB.

AirCard 875 beroperasi pada frekwensi 850, 1800, 1900 dan 2100 MHz. Dengan jangkauan tersebut AirCard 875 dapat digunakan diseluruh dunia. Ketika tidak dapat menemukan sinyal HSDPA, AirCard 875 tetap berusaha menyediakan koneksi internet dengan memanfaatkan jaringan EDGE. Jika kondisi berubah seperti itu, kami menyarankan Anda untuk menghubungkannya ke ponsel ketimbang laptop karena menggunakan jaringan EDGE pada laptop terkadang menimbulkan speaker pada laptop mengeluarkan suara mendengung yang muncul secara periodik. Mengingat semua operator penyedia jaringan HSDPA saat ini berlomba-lomba menggaet lebih banyak pelanggan, kualitas yang ditawarkan juga makin baik sehingga dapat dikatakan hilangnya sinyal HSDPA yang menyebabkan sinyal beralih ke EDGE sangat jarang terjadi.

Dengan mempertimbangkan luasnya frekwensi yang didukung, kami memutuskan untuk memilih AirCard 875 dan mencobanya pada saat melakukan kunjungan ke Barcelona. Tanpa melakukan konfigurasi ulang, kami mendapatkan kecepatan diatas 300 Kbps dengan kecepatan puncak sebesar 650 Kbps. Tidak secepat pada saat menggunakannya di rumah, tetapi kami tetap mendapatkan sinyal HSDPA dengan baik.

Kesimpulan

Sierra AirCard 875 merupakan pilihan yang baik untuk koneksi internet berkecapatan tinggi pada laptop. Meskipun pada AirCard 875U USB Anda akan menemukan tambahan fleksbilitas karena port yang digunakan adalah USB, AirCard 875 justru tidak akan merepotkan Anda dengan rutinitas pasang-copot pada saat sebelum dan setelah penggunaan karena Anda hanya perlu memasang AirCard 875 sekali saja pada slot PCMCIA dan tidak perlu melepasnya lagi, mengingat saat ini hampir tidak ada piranti lain yang menggunakan slot PCMCIA. Lain halnya dengan port USB yang sangat sibuk melayani berbagai berbagai piranti. (ella)

Detail Specifications :

Features
- Wireless data at speeds up to 3.6 Mbps on HSDPA capable networks
- High performance antenna in rugged housing
- Simultaneous voice (voip) and data capabilities
- Supports HSDPA and UMTS on the 2100, 1900, 850 Mhz band
- Supported by Sierra Wireless developer tools for third party user interface and applications
SIM Compatibility GSM
System Requirements
- Type II PC Card Slot
- 300 MHz Processor
- 256MB RAM
- Internet Explorer 5.5 or later
- 40MB Available Hard Disk Space
OS Compatibility Windows® Vista, XP, 2000
Others Includes:
- AirCard 875 LaptopConnect Card
- Connectivity Software
- Quick Start Guide

Monday, September 8, 2008

Terminal Services Gateway and Resulting Internet Communication in Windows Server 2008

In This Section

Benefits and Purposes of Terminal Services Gateway

Examples of Security-Related Features in Terminal Services Gateway

Procedure for Viewing or Changing Group Policy Settings that Affect TS Gateway in Windows Server 2008

Additional References

This section provides overview information about Terminal Services Gateway and information about some Group Policy settings that affect Terminal Services Gateway. The section also provides suggestions for other sources of information about Terminal Services Gateway (TS Gateway), to help you balance your organization’s requirements for communication across the Internet with your organization’s requirements for protection of networked assets. However, it is beyond the scope of this white paper to describe all aspects of maintaining appropriate levels of security in an organization running servers that use Terminal Services Gateway to support remote users who are communicating across the Internet.

Benefits and Purposes of Terminal Services Gateway

TS Gateway is a role service that enables authorized remote users to connect to resources on an internal corporate or private network, from any Internet-connected device that can run the Remote Desktop Connection (RDC) client. The network resources can be terminal servers, terminal servers running RemoteAppTM programs, or computers with Remote Desktop enabled.

TS Gateway uses the Remote Desktop Protocol (RDP) over Hypertext Transfer Protocol Secure (HTTPS) to establish an encrypted connection between remote users on the Internet and the internal network resources on which their productivity applications run.

TS Gateway enables remote users to connect to internal network resources over the Internet, by using an encrypted connection, without needing to configure virtual private network (VPN) connections.

For more information about TS Gateway, see Additional References, later in this section.

Examples of Security-Related Features in Terminal Services Gateway

TS Gateway includes a variety of settings and features related to security, some of which are described in the following list. For additional information about security-related improvements in TS Gateway, see Additional References later in this topic.

  • TS Gateway provides a comprehensive security configuration model that enables you to control access to specific internal network resources.
  • TS Gateway provides a point-to-point RDP connection, rather than allowing remote users access to all internal network resources.
  • TS Gateway enables most remote users to connect to internal network resources that are hosted behind firewalls in private networks and across network address translators (NATs). With TS Gateway, you do not need to perform additional configuration for the TS Gateway server or clients for this scenario.
    Prior to this release of Windows Server, security measures prevented remote users from connecting to internal network resources across firewalls and NATs. This is because port 3389, the port used for RDP connections, is typically blocked for network security purposes at the firewalls. TS Gateway transmits RDP traffic to port 443 instead, by using an HTTP Secure Sockets Layer/Transport Layer Security (SSL/TLS) tunnel. Because most corporations open port 443 to enable Internet connectivity, TS Gateway takes advantage of this network design to provide remote access connectivity across multiple firewalls.
  • The TS Gateway Manager snap-in console enables you to configure authorization policies to define conditions that must be met for remote users to connect to internal network resources. For example, you can specify:
    • Who can connect to network resources (in other words, the user groups who can connect).
    • What network resources (computer groups) users can connect to.
    • Whether client computers must be members of Active Directory security groups.
    • Whether device and disk redirection is allowed.
    • Whether clients need to use smart card authentication or password authentication, or whether they can use either method.
  • You can configure TS Gateway servers and Terminal Services clients to use Network Access Protection (NAP) to further enhance security. NAP is a health policy creation, enforcement, and remediation technology that is included in Windows XP Service Pack 2, Windows Vista, and Windows Server 2008. With NAP, system administrators can enforce health requirements, which can include software requirements, security update requirements, required computer configurations, and other settings.
    noteNote
    Computers running Windows Server 2008 cannot be used as NAP clients when TS Gateway enforces NAP. Only computers running Windows XP SP2 and Windows Vista can be used as NAP clients when TS Gateway enforces NAP.
    For information about how to configure TS Gateway to use NAP for health policy enforcement for Terminal Services clients that connect to TS Gateway servers, see topics about deploying TS Gateway on the Microsoft Web site at:
    http://go.microsoft.com/fwlink/?LinkId=106400
  • You can use TS Gateway server with Microsoft Internet Security and Acceleration (ISA) Server to enhance security. In this scenario, you can host TS Gateway servers in a private network rather than a perimeter network (also known as a DMZ, demilitarized zone, and screened subnet), and host ISA Server in the perimeter network. The SSL connection between the Terminal Services client and ISA Server can be terminated at the ISA Server, which is Internet-facing.
    For information about how to configure ISA Server as an SSL termination device for TS Gateway server scenarios, , see topics about deploying TS Gateway on the Microsoft Web site at:
    http://go.microsoft.com/fwlink/?LinkId=106400
  • The TS Gateway Manager snap-in console provides tools to help you monitor TS Gateway connection status, health, and events. By using TS Gateway Manager, you can specify events (such as unsuccessful connection attempts to the TS Gateway server) that you want to monitor for auditing purposes.

Procedure for Viewing or Changing Group Policy Settings that Affect TS Gateway in Windows Server 2008

The following procedure tells how to view or change Group Policy settings that affect TS Gateway in Windows Server 2008.

To View or Change Group Policy Settings that Affect TS Gateway

  1. As needed, see Appendix B: Resources for Learning About Group Policy for Windows Server 2008, and then edit an appropriate Group Policy object (GPO).
  2. Expand User Configuration, expand Policies (if present), expand Administrative Templates, expand Windows Components, expand Terminal Services, and then click TS Gateway.
  3. In the details pane, double-click each setting that you want to view or change. If you want more information about a setting, double-click the setting and then click the Explain tab.
    For all of these settings, if you select Enabled, you can then select or clear a check box labeled Allow users to change this setting. The settings are as follows:
    • Set TS Gateway authentication method
    • Enable connection through TS Gateway
    • Set TS Gateway server address

Additional References