Grandstream Networks HandyTone-286 Manual Do Utilizador

 
 

39 

OBP/SBCs to allow the use of VoIP protocols from private networks with 

internet

 connections 

using 

NAT

. 

Point-to-Point Protocol over Ethernet, is a network protocol for encapsulating PPP frames in 
Ethernet frames. It is used mainly with cable modem and DSL services. 

 
PSTN  

Public Switched Telephone Network 

i.e. the phone service we use for every ordinary phone call, or called POT (Plain Old 
Telephone), or circuit switched network. 

Real-time Transport Control Protocol, defined in 

RFC 3550

, a sister protocol of the 

Real-time 

Transport Protocol

 (RTP), It partners RTP in the delivery and packaging of multimedia data, 

but does not transport any data itself. It is used periodically to transmit control packets to 
participants in a streaming multimedia session. The primary function of RTCP is to provide 
feedback on the quality of service being provided by RTP. 

Real-time Transport Protocol defines a standardized packet format for delivering audio and 
video over the Internet. It was developed by the Audio-Video Transport Working Group of the 

IETF

 and first published in 1996 as 

RFC 1889

 

Session Description Protocol, is a format for describing 

streaming media

 initialization 

parameters. It has been published by the 

IETF

 as 

RFC

 2327. 

Session Initiation Protocol, An IP telephony signaling protocol developed by the IETF 
(RFC3261). SIP is a text-based protocol suitable for integrated voice-data applications. SIP is 
designed for voice transmission and uses fewer resources and is considerably less complex than 
H.323. 
All Grandstream products are SIP based 

Simple Traversal of UDP over NATs, is a 

network protocol

 allowing clients behind 

NAT

 (or 

multiple NATs) to find out its public address, the type of NAT it is behind and the internet side 
port associated by the NAT with a particular local port. This information is used to set up UDP 
communication between two hosts that are both behind NAT routers. The protocol is defined in 

RFC 3489

. STUN will usually work good with non-symmetric NAT routers.