dynamic tunneling configuration for network with uni-directional link
DESCRIPTION
Dynamic Tunneling Configuration for Network with Uni-Directional Link. ICCC99 – 15/09/1999 Mikiyo NISHIDA / KEIO Univ. Hiroyuki KUSUMOTO / KEIO Univ. Jun MURAI / KEIO Univ. General Description. Introdunction Characteristics of Uni-Directional Link Current Problems of Uni-Directional Link - PowerPoint PPT PresentationTRANSCRIPT
Dynamic Tunneling Configuration for Network with Uni-Directional Link
ICCC99 – 15/09/1999
Mikiyo NISHIDA / KEIO Univ.
Hiroyuki KUSUMOTO / KEIO Univ.
Jun MURAI / KEIO Univ.
General Description
• Introdunction– Characteristics of Uni-Directional Link
• Current Problems of Uni-Directional Link• Scheme
– Dynamic Tunneling Configuration
• Design– Message based mechanism
• Implementation– Implement our mechanism
• Conclusion
Introduction(1) UDL
• Uni Directional Link– One-way (most case:Multiple Access)data link
• Satellite
• Cable TV
Introduction(2) Network with UDL
• Network with UDL & BDL (Bi-Directional Link)– We assume UDL
network in the Internet has UDL and another BDL accessibility
Introduction(3)Tunneling Techniques
• For Simulating link solution– tunneling
• Current Tunneling Scheme– Static Configuration– Few Scalability– Too much management cost
We propose‘ Dynamic Tunnel Configuration Scheme’
Current Problems(1)Routing in network with UDL
• Current Internet Routing Protocol– Based on Link Bi-directonality
• Approaches for using UDL network– Modify Routing Protocol– Provide Bi-Directional accessibility for UDL vi
rtually
Current Problems(2) Data-link address resolution in UDL
• Multiple access data-link requires data-link address resolution– Ethernet use ARP protocol
Current Problems(3)IP Address Assignment in UDL
• UDL has a lot of receivers
• IP address is limited resource
Current Problems - Overall
• Routing Problems
• Data-link address resolution
• IP Address Assignment
Dynamic Tunneling Scheme(1)
• We propose Dynamic Tunneling Configuration Scheme– Provide virtual return path of UDL
automatically– Provide mechanism of data-link address
resolution on UDL– Provide mechanism of IP address dynamic
assignment
Dynamic Tunneling Scheme(2)
• Message based mechanism– Exchange messages over UDL and BDL– UDL Keepalive– Setup/Shutdown tunnel– Data-link address resolution– IP Address Automatically Assignment
Design(1) General Description
Design(2) Messages
• Notify Message (via UDL)– Sender to Receiver
• HELLO message– Notify Sender Information
– Applied UDL Keep Alive
Design(3) Messages
• Control Message (via BDL)– Exchange each other
• REQUEST Message (Receiver to Sender)– Notify Receiver beginning to use UDL– Request Tunnel Setup, IP Address Assign
• REPLY Message (Sender to Receiver)– Reply for Receiver’s message
• REFRESH/RELEASE Message (Receiver to Sender)– Notify Receiver uses UDL continuously / terminate using
UDL
Design(4) Modules
• Virtual Link Module– Manipulate tunneling packets
• Control Module– Manipulate messages– Set/Release tunnel– Set/Release interface’s IP address– Maintain IP/DL address
Design(5) Operating cycle
Implementation(1)
• Target Architecture:– FreeBSD 2.2.1-Release
• Modified data-link routine in Unix Kernel• UDL: Use Ethernet (Modified Output Routine)
• BDL: Use Ethernet
• Virtual Link Module is implemented in Unix Kernel
• Control Module is implemented as user process application
Implementation(2) Virtual Link Module
• Total of 120 lines:– if_ethersubr.c
• ether_input(), ether_output()
• Add encapsulation/decapsulation function
– if.c• if_ioctl()
• Add manipulating tunnel information function
Implementation(3)Control module
• Code size– Total of 1450 lines / at Receiver– Total of 1436 lines / at Sender
• Implement as user process application
• Send and receive messages via UDP
• Maintenance DL/IP address table
Conclusion
• Describe current problems of network with unidirectional link
• Propose Dynamic Tunnel Configuration Scheme
• Implement our proposed mechanism
• Present usability of this scheme
Future Work
• Test many types of routing protocols
• Improve performance and scalability