STUN和TURN技术浅析
STUN (Session Traversal Utilities for NAT) is a standardized set of methods and a network protocol to allow an end host to discover its public IP address if it is located behind a NAT. It is used to permit NAT traversal for applications of real-time voice, video, messaging, and other interactive IP communications. It is documented in RFC 5389. The STUN URI scheme is documented in RFC 7064. STUN is intended to be a tool to be used by other protocols, such as ICE.
The STUN protocol allows applications operating behind a network address translator (NAT) to discover the presence of the network address translator and to obtain the mapped (public) IP address (NAT address) and port number that the NAT has allocated for the application's User Datagram Protocol (UDP) connections to remote hosts. The protocol requires assistance from a third-party network server (STUN server) located on the opposing (public) side of the NAT, usually the public Internet.
其他资料:
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Characterization and Measurement of TCP Traversal through NATs and FirewallsPDF:
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Peer-to-Peer Communication Across Network Address Translators:google搜素"穿越NAT的p2p通信方法研究
restund 安装使用手册
http://nil.uniza.sk/sip/installing-and-configuring-restund-stunturn-server
Installing and configuring Restund - STUN/TURN server
Submitted by paulus on Tue, 02/21/2012 - 23:02
This guide describes how to install and configure RESTUND STUN/TURN server for supporting TURN functionality.
This sollution is still in TESTING STATE!!!
TURN server seems to work properly, but sometimes the klient channel allocation on server side is not working and the media stream wont start!
Testing with: Restund v0.4.0, Kamailio v3.2, X-lite 4.
First we need to install compiler g++ and make:
$apt-get install g++ make
The instalation and configuration of RESTUND STUN/TURN server takes more steps (official site http://www.creytiv.com/restund.html).
The first sten is installing libre (Toolkit library for asynchronous network IO with protocol stacks including SIP, SDP, RTP, STUN, TURN, ICE, BFCP and DNS):
$wget http://www.creytiv.com/pub/re-0.4.0.tar.gz
$tar xf re-0.4.0.tar.gz
$cd re-0.4.0/
$make
$make install
Now we can install the STUN/TURN server:
$wget http://www.creytiv.com/pub/restund-0.4.0.tar.gz
$tar xf restund-0.4.0.tar.gz
$cd restund-0.4.0/
$make
$make install
And finally the configuration file. The sample configuration file is in restund etc directory:
joe .../restund-0.4.0/etc/restund.conf
Hint: Some notes about configuration file items could be find in .../restund/docs/restund.txt
Following changes in configuration file will provide the basic TURN server functionality:
debug yes
syncinterval 600
udp_listen 158.193.139.47:3478 #YOUR IP ADDRESS
udp_listen 158.193.139.48:3478 #YOUR IP ADDRESS
udp_sockbuf_size 524288
tcp_listen 158.193.139.47:3478 #YOUR IP ADDRESS
tcp_listen 158.193.139.48:3478 #YOUR IP ADDRESS
# modules
module_path /usr/local/lib/restund/modules
module stat.so
module binding.so
#module auth.so #no authentication configured, so comment
module turn.so
#module mysql_ser.so #Mysql not yes supported, so comment
module syslog.so
module status.so
# turn
turn_max_allocations 512
turn_max_lifetime 600
turn_relay_addr 158.193.139.47 #YOUR IP ADDRESS
#turn_relay_addr6 ::1 #comment if not using IPv6
#Mysql not yes supported, so comment following lines
# mysql
#mysql_host localhost
#mysql_user ser
#mysql_pass heslo
#mysql_db ser
After making changes above copy the configuration file into /etc/ directory:
$cp .../restund-0.4.0/etc/restund.conf /etc/
刚安装完 *.so动态库，需要刷新动态库的信息 ldconfig -p 可以看到动态库信息是否更新了，不更新，无法使用
$sudo ldconfig
To run RESTUND STUN/TURN server use following command:
$restund /etc/restund.conf
With debbuging mode on following message (or similar) appear:
udp listen: 158.193.139.47:3478 udp listen: 158.193.139.48:3478
tcp listen: 158.193.139.47:3478
tcp listen: 158.193.139.48:3478
stat: module loaded
binding: module loaded
turn: lifetime=120 ext=158.193.139.47 ext6=? bsz=1024
syslog: module loaded facility=24
status: module loaded (udp=127.0.0.1:33000 http=158.193.139.47:8080)
To see the actual status of your TURN server, we need to install apache server:
$apt-get install apache2
And next do following changes in configuration file:
# status
#status_udp_addr 127.0.0.1 #comment
#status_udp_port 33000 #comment
status_http_addr 158.193.139.47 #YOUR IP ADDRESS
status_http_port 8080 #port for http access
Restart your RESTUND STUN/TURN server. Now you are able to if your server is running and how long with your web browser:
http://YOUR_IP_ADDRESS:8080
