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Grandstream Networks Grandstream BudgeTone 200 User Manual

Page 52

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52


NAT

Network Address Translation


NTP

Network Time Protocol

, a protocol to exchange and synchronize time over

networks
The port used is UDP 123
Grandstream products using NTP to get time from Internet


OBP/SBC

Outbound Proxy or another name Session Border Controller. A device used in

VoIP

networks. OBP/SBCs are put into the signaling and media path between

calling and called party. The OBP/SBC acts as if it was the called VoIP phone and
places a second call to the called party. The effect of this behaviour is that not
only the signaling traffic, but also the media traffic (voice, video etc) crosses the
OBP/SBC. Without an OBP/SBC, the media traffic travels directly between the
VoIP phones. Private OBP/SBCs are used along with

firewalls

to enable VoIP

calls to and from a protected enterprise network. Public VoIP service providers
use OBP/SBCs to allow the use of VoIP protocols from private networks with

internet

connections using

NAT

.




PPPoE

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.


RTCP

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.


RTP