问题描述：
英语翻译
Tunneling is a method of using an internetwork infrastructure to transfer data for one network over another network.The data to be transferred (or payload) can be the frames (or packets) of another protocol.Instead of sending a frame as it is produced by the originating node,the tunneling protocol encapsulates the frame in an additional header.The additional header provides routing information so that the encapsulated payload can traverse the intermediate internetwork.
The encapsulated packets are then routed between tunnel endpoints over the internetwork.The logical path through which the encapsulated packets travel through the internetwork is called a tunnel.Once the encapsulated frames reach their destination on the internetwork,the frame is decapsulated and forwarded to its final destination.Tunneling includes this entire process (encapsulation,transmission,and decapsulation of packets).
The transit internetwork can be any internetwork-the Internet is a public internetwork and is the most widely known real world example.There are many examples of tunnels that are carried over corporate internetworks.And while the Internet provides one of the most pervasive and cost-effective internetworks,references to the Internet in this paper can be replaced by any other public or private internetwork that acts as a transit internetwork.
Tunneling technologies have been in existence for some time.Some examples of mature technologies include:SNA tunneling over IP internetworks.When System Network Architecture (SNA) traffic is sent across a corporate IP internetwork,the SNA frame is encapsulated in a UDP and IP header
IPX tunneling for Novell NetWare over IP internetworks.When an IPX packet is sent to a NetWare server or IPX router,the server or the router wraps the IPX packet in a UDP and IP header,and then sends it across an IP internetwork.The destination IP-to-IPX router removes the UDP and IP header and forwards the packet to the IPX destination.
New tunneling technologies have been introduced in recent years.These newer technologies-which are the primary focus of this paper-include:
Point-to-Point Tunneling Protocol (PPTP).PPTP allows IP,IPX,or NetBEUI traffic to be encrypted,and then encapsulated in an IP header to be sent across a corporate IP internetwork or a public IP internetwork such as the Internet.
Layer Two Tunneling Protocol (L2TP).L2TP allows IP,IPX,or NetBEUI traffic to be encrypted,and then sent over any medium that supports point-to-point datagram delivery,such as IP,X.25,Frame Relay,or ATM.
IPSec tunnel mode.IPSec tunnel mode allows IP packets to be encrypted,and then encapsulated in an IP header to be sent across a corporate IP internetwork or a public IP internetwork such as the Internet.
Tunneling is a method of using an internetwork infrastructure to transfer data for one network over another network.The data to be transferred (or payload) can be the frames (or packets) of another protocol.Instead of sending a frame as it is produced by the originating node,the tunneling protocol encapsulates the frame in an additional header.The additional header provides routing information so that the encapsulated payload can traverse the intermediate internetwork.
The encapsulated packets are then routed between tunnel endpoints over the internetwork.The logical path through which the encapsulated packets travel through the internetwork is called a tunnel.Once the encapsulated frames reach their destination on the internetwork,the frame is decapsulated and forwarded to its final destination.Tunneling includes this entire process (encapsulation,transmission,and decapsulation of packets).
The transit internetwork can be any internetwork-the Internet is a public internetwork and is the most widely known real world example.There are many examples of tunnels that are carried over corporate internetworks.And while the Internet provides one of the most pervasive and cost-effective internetworks,references to the Internet in this paper can be replaced by any other public or private internetwork that acts as a transit internetwork.
Tunneling technologies have been in existence for some time.Some examples of mature technologies include:SNA tunneling over IP internetworks.When System Network Architecture (SNA) traffic is sent across a corporate IP internetwork,the SNA frame is encapsulated in a UDP and IP header
IPX tunneling for Novell NetWare over IP internetworks.When an IPX packet is sent to a NetWare server or IPX router,the server or the router wraps the IPX packet in a UDP and IP header,and then sends it across an IP internetwork.The destination IP-to-IPX router removes the UDP and IP header and forwards the packet to the IPX destination.
New tunneling technologies have been introduced in recent years.These newer technologies-which are the primary focus of this paper-include:
Point-to-Point Tunneling Protocol (PPTP).PPTP allows IP,IPX,or NetBEUI traffic to be encrypted,and then encapsulated in an IP header to be sent across a corporate IP internetwork or a public IP internetwork such as the Internet.
Layer Two Tunneling Protocol (L2TP).L2TP allows IP,IPX,or NetBEUI traffic to be encrypted,and then sent over any medium that supports point-to-point datagram delivery,such as IP,X.25,Frame Relay,or ATM.
IPSec tunnel mode.IPSec tunnel mode allows IP packets to be encrypted,and then encapsulated in an IP header to be sent across a corporate IP internetwork or a public IP internetwork such as the Internet.
问题解答：
我来补答展开全文阅读