1 / 18

RFC 3361: DHCP Option for SIP Servers

RFC 3361: DHCP Option for SIP Servers. Speaker: Chung yu Wu Teacher: Quincy Wu. Outline. Introduction DHCP DNS SIP server DHCP option Security Considerations Conclusion References. Introduction. This document defines a DHCP option that contain that contains a list of domains or

waseem
Download Presentation

RFC 3361: DHCP Option for SIP Servers

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. RFC 3361:DHCP Option for SIP Servers Speaker: Chung yu Wu Teacher: Quincy Wu

  2. Outline • Introduction • DHCP • DNS • SIP server DHCP option • Security Considerations • Conclusion • References CSIE

  3. Introduction • This document defines a DHCP option that contain that contains a list of domains or IPv4 address that can be mapped to one or more SIP outbound proxy servers。 CSIE

  4. Introduction (cont) Outbound proxy server SIP server SIP request message URL Outbound SIP request SIP response message SIP request message SIP response message RTP Media stream User agent client CSIE User agent server

  5. DHCP • The Dynamic Host Configuration Protocol is a mechanism for having a DHCP server distribute IP addresses to DHCP client systems on a network。 • Can provide a DHCP client with a full set of TCP/IP configuration values，such as netmask，gateway address etc。 CSIE

  6. Configuration values • IP ex:10.10.16.31 • netmask ex:255.255.255.0 • gateway ex:10.10.16.254 • DNS IP ex:163.22.2.1 CSIE

  7. DHCP Operation • Find DHCP server • DHCPDISCOVER • Offer IP to rent the address • DHCPOFFER • Accept IP lease • DHCPREQUEST • The lease confirming • DHCPACK CSIE

  8. DHCP Operation (cont) DHCP client DHCP server Ethernet 1.DHCPDISCOVER 2.DHCPOFFER 3.DHCPREQUEST 4.DHCPACK CSIE

  9. DNS • DNS is an Internet-wide service that provides mappings between IP addresses and hostnames。 • The DNS is a distributed database implemented in a hierarchy of name servers。 • The DNS is also an application-layer protocol • IP address — a 32 bit identifier used for addressing hosts and routing data to them • Hostname — an ASCII string used by applications CSIE

  10. DNS (cont) Search www.ncnu.edu.tw Search root Cache memory response root Name server Search tw tw hk response tw Name server DNS server Search edu.tw edu com Search DNS response edu.tw Response DNS Name server Search ncnu.edu.tw ncnu nctu response ncnu.edu.tw CSIE DNS client Name server

  11. SIP server DHCP option • SIP server DHCP option has two encoding: 1. encoding byte value ‘enc’=0 list of domain names 2. encoding byte value ‘enc’=1 one or more IPv4 address • ‘Len’: the total number of octets in the option, including the encoding byte • A DHCP server MUST NOT mix the two encoding in the same DHCP message. • The code for this option is 120 CSIE

  12. Domain Name List • The DHCP option for this encoding has the following format: Code Len enc DNS name of SIP server CSIE

  13. Example of Domain Name List • Ex: ncnu.edu and ncnu.com CSIE

  14. IPv4 Address List • The DHCP option for this encoding has the following format: • Minimum length is 5 • The length MUST be a multiple of 4 plus one Code Len enc Address 1 Address 2 CSIE

  15. Example of IPv4 Address List Display the address CSIE

  16. Security Considerations • Modify the response from a DHCP server • SIP user agent could be led to contact a rogue SIP server， possibly one that then intercepts call requests or denies service。 CSIE

  17. Conclusion • Defines DHCP option: -List of domain names -IPv4 address • Can be mapped to one or more SIP outbound proxy servers CSIE

  18. References • RFC 2131 Dynamic Host Configuration Protocol • RFC3261 Session Initiation Protocol • RFC2119 Key words for use in RFCs to indicate requirement levels CSIE

More Related