Grandstream Networks GXW-410xv User Manual

Page 29

MTU A Maximum Transmission Unit (MTU) is the largest size

packet

frame

, specified in

octet

s (eight-

t. The maximum for

thernet is 1500 byte.

AT Network Address Translation

bit bytes), that can be sent in a packet- or frame-based network such as the Interne
E

N

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
behavior 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 ne

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

twork.

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. The phone service we use for every ordinary phone call, or

port Control Protocol, defined in

RFC 3550

called POT (Plain Old Telephone), or circuit switched network.

RTCP Real-time Trans

, a sister protocol of the

Real-time

Transport Protocol

(RTP), It partners RTP in the delivery and packaging of multimedia data, but does not

riodically to transmit control packets to participants in a streaming

ultimedia session. The primary function of RTCP is to provide feedback on the quality of service being

TP Real-time Transport Protocol defines a standardized packet format for delivering audio and video

transport any data itself. It is used pe
m
provided by RTP.

R
over the Internet. It was developed by the Audio-Video Transport Working Group of the

IETF

and first

published in 1996 as

RFC 1889

SDP Session Description Protocol is a format for describing

streaming media

initialization parameter

has been published by the

s. It

IETF

RFC

2327.

SIP 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

ansmission and uses fewer resources and is considerably less complex than H.323. All Grandstream

TUN Simple Traversal of UDP over NATs is a

network protocol

tr
products are SIP based

S

allowing clients behind

NAT

(or multiple

et up UDP communication between two

osts that are both behind NAT routers. The protocol is defined in

RFC 3489

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 s
h

. STUN will usually work well

with non-symmetric NAT routers.

TCP Transmission Control Protocol is one of the core protocols of the

Internet protocol suite

. Using TCP

applications on networked hosts can create connections to one another, over which they can exchange
data or

packets

. The protocol guarantees reliable and in-order delivery of sender to receiver data.

TFTP Trivial File Transfer Protocol, is a very simple

file

transfer

protocol

, with the functionality of a very