Vöčuol Netwörk Kompyutiŋ (suokxie-wa VNK) wa skrīn šäriŋ en rīmot koncrol softwär. | VNC(Virtual Network Computing),為一種使用RFB協定的螢幕畫面分享及遠端操作軟體。此軟體藉由網路,可傳送鍵盤與滑鼠的動作及即時的螢幕畫面。 |
VNC與作業系統無關,因此可跨平台使用,例如可用Windows連線到某Linux的電腦,反之亦同。甚至在沒有安裝用戶端程式的電腦中,只要有支援JAVA的瀏覽器,也可使用。 |
History / Històri / 歷史[]
VNC由Olivetti & Oracle研究室所開發,此研究室在1999年併入美國電話電報公司(AT&T)。AT&T於2002年中止了此研究室的運作,並把VNC以GPL釋出。
參與VNC開發的人員有:
- Tristan Richardson(發明者)
- Andy Harter(專案經理)
- Quentin Stafford-Fraser
- James Weatherall
- Ken Wood
- Andy Hopper
- Charles McLachlan
- Paul Webster
2002年研究室中止運作之後,部份團隊中的成員另起爐灶開發出RealVNC。
原理[]
VNC分為三個部份:
- VNC伺服程式:將螢幕畫面分享出來
- VNC用戶端:與VNC伺服程式互動
- VNC協定:最簡單的圖像協定──將組成某塊矩形的點的資料填入位置X、Y之處
由於VNC需傳送圖像資料,因此會耗費較大的頻寬。VNC程式可讓使用者調整畫面的色彩數、解析度等,以配合各種不同的頻寬,以有較佳的效能。
VNC預設使用TCP埠5900至5906,而JAVA的VNC用戶端使用5800至5806。
UNIX上的VNC稱為xvnc,同時扮演兩種角色,對X-Window的應用程式來說它是X server,對於VNC用戶端來說它是VNC伺服程式。
Security / Sekyuriti / 安全性[]
By default, VNC is not a secure protocol. While passwords are not sent in plain-text (as in telnet), brute-force cracking could prove successful if both the encryption key and encoded password are sniffed from a network. For this reason it is recommended that a password of at least 8 characters be used. On the other hand, there is also an 8-character limit on some versions of VNC; if a password is sent exceeding 8 characters, the excess characters are removed and the truncated string is compared to the password. | VNC並非是安全的協定,雖然VNC伺服程式需設定密碼才可接受外來連線,且VNC用戶端與VNC伺服程式之間的密碼傳輸經過加密,但仍可被輕易的攔截到並使用暴力法破解。 |
However, VNC may be tunnelled over an SSH or VPN connection which would add an extra security layer with stronger encryption. SSH clients are available for all major platforms (and many smaller platforms as well); SSH tunnels can be created from UNIX clients, Microsoft Windows clients, Macintosh clients (including Mac OS X and System 7 and up) – and many others. There are freeware applications that create instant VPN tunnels between computers such as Remobo. Hamachi which has been purchased by LogMeIn and is no longer freeware, though it's free for non-commercial use. | 不過VNC可設計以SSH或VPN傳輸,以增加安全性。 |
UltraVNC supports the use of an open-source encryption plugin which encrypts the entire VNC session including password authentication and data transfer. It also allows authentication to be performed based on NTLM and Active Directory user accounts. However, use of such encryption plugins make it incompatible with other VNC programs. RealVNC offers high-strength encryption as part of its commercial package. Workspot released AES encryption patches for VNC. | UltraVNC sùpport yusing gunghoi kontent mide the use of an open-source encryption plugin which encrypts the entire VNC session including password authentication and data transfer. It also allows authentication to be performed based on NTLM and Active Directory user accounts. However, use of such encryption plugins make it incompatible with other VNC programs. RealVNC offers high-strength encryption as part of its commercial package. Workspot released AES encryption patches for VNC. | 有些VNC軟體,如UltraVNC,更進一步支援Active Directory及NTLM的帳號密碼認證。
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List of VNC software / VNK softwär list / VNC軟體列體[]
Bikos VNK wa laisènsen bai GPL, soi severol VNK softwär wa diraiven:
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由於VNC以GPL授權,衍生出了幾個VNC軟體:
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這些軟體各有所長,例如UltraVNC支援檔案傳輸以及全螢幕模式。而這些軟體間大多遵循基本的VNC協定,因此大多可互通使用。 |
See also / Si osou / 參看[]
- Remote Desktop/Rīmot Desktop/遠端桌面
- Remote Desktop Protocol/Rīmot Desktop Protokol/遠端桌面協定
- Virtual private network
- Comparison of remote desktop software
- X Window System
- NeoRouter, a P2P VPN program that extends the VNC connections over the Internet
- Remobo, which can run VNC over its Instant Private Network.
- 遠端操作
- Terminal Service
External links / Ikstörnol liŋks / 外部連結[]
Wikimedia Commons has media related to:
- VNC AT&T的VNC原始版本存檔頁
- Gentoo-wiki/VNC
- RFB 3.8 Protocol Standard
- RealVNC
- TightVNC
- UltraVNC
- Vine Viewer - A VNC client for OSX