Carrier Grade Voice over IP notes

*Standard Track
Internet draft→RFC→proposed standard (if 有兩個成功實作 and interoperability)→draft standard→standard(with a standard number,STD==RFC number)
*advantage of VoIP :

• lower equipment cost
• lower operating expense
• integration of voice and data
• potentially lower bandwidth
• the wide spread availability

TCP Port numbers
well-known port numbers:0~1023
telnet:23,SMTP:25
IP address + prot number = socket address
TCP header format
Sequence number: count data octets
ack number: the next segment number that the receiver is expecting