Grandstream Networks BT200 User Manual
Page 34
Grandstream Networks, Inc.
BT-200 User Manual
Page 34 of 35
Firmware 1.1.1.14
Last Updated: 12/2006
MTU A Maximum Transmission Unit (MTU) is the largest size
bit bytes), that can be sent in a packet- or frame-based network such as the Internet. The maximum for
Ethernet is 1500 byte.
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
OBP/SBCs are put into the signaling and media path between calling and called Caller. The OBP/SBC
acts as if it was the called VoIP phone and places a second call to the called Caller. 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
ected enterprise network.
Public VoIP service providers use OBP/SBCs to allow the use of VoIP protocols from private networks
connections using
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
called POT (Plain Old Telephone), or circuit switched network.
RTCP Real-time Transport Control Protocol, defined in
, a sister protocol of th
(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 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
published in 1996 as
SDP Session Description Protocol is a format for describing
nitialization parameters. It
has been published by the
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
transmission and uses fewer resources and is considerably less complex than H.323. All Grandstream
products are SIP based
STUN Simple Traversal of UDP over NATs is a
allowing clients behind
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
. STUN will usually work well
with non-symmetric NAT routers.
TCP Transmission Control Protocol is one of the core protocols of the
. Using TCP,
applications on networked hosts can create connections to one another, over which they can exchange
col guarantees reliable and in-order delivery of sender to receiver data.
TFTP Trivial File Transfer Protocol, is a very simple
, with the functionality of a very
basic form of
; It uses
(port 69