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G.711
Describes the 64 kbps pulse code modulation voice coding technique. Specifies two laws of compression. The law A and the law M. G711 takes a sample every 8Khz - 8000 samples per second. 1 sample every 125 micro second. Authorize a bandwidth of 4000 Hz. Both laws are generating 8 * 8000 bps = 64 Kbit /s.
The A Law Used mainly in Europe. The M Law Used in the USA and Japan.
G.723.1
Describes a compression technique that can be used for compressing speech and audio signal components at a very low bit rate as part of the H.323 family of standards. This codec has two bit rates associated with it; 5.3 and 6.3 kpbs. The higher bit rate is based on ML-MLQ technology and provides a somewhat higher quality of sound. The lower bit rate is based on CELP and provides system designers with additional flexibility. Describes in the ITU-T standard in G-series recommendations.
G.726
Describes ADPCM coding at 40, 32, 24 and 16 kbps. ADPCM encoded voice can be interchanged between packet voice, PSTN, and PBX networks if the PBX networks are configured to support ADPCM. Described in the ITU-T standard in its G-series recommendations.
G.728
Describes a 16 kbps low-delay variation of CELP voice compression. CELP voice coding must be translated into a public telephony format for delivery to or through the PSTN. Described in the ITU-T standard in its G-series recommendations.
G.729
Describes CELP compression where voice is coded into 8 kbps streams. The two variations of this standard G.729 and G.729 annex A, differ mainly in computational complexity; both provide speech quality similar to 32 kbps ADPCM.
G.733 / T1
Also called T1
| Features |
E1 G732 |
T1 G733 |
| Time laps per frame of 125 micro second |
32 |
24 |
| Voice channels per frame |
30 |
24 |
| Bit per frame |
256 |
193 |
| Line speed |
2.048 Mbps |
1.544 Mbps |
Gatekeeper
An H.323 entity on the LAN that provides address translation and control access the the LAN H.323 terminals and gateways.
A gatekeeper maintains a registry of devices in the multimedia network. The devices register with the gatekeeper at startup, and request admission to a call from the gatekeeper. The gatekeeper is an H.323 entity on the LAN that provides address translation and control access to the LAN for H.323 terminals and gateways. The gateway may provide other services to the H.323 terminals and gateways, such as bandwidth management and locating gateways.
Gateway
- In this example the remote site gets the access to the host using a controller plugged onto the LAN.
- You can have thousands of workstations accessing the host.
Gb
Gigabit 1 billion bits
GB
Giga Bytes - 1,073,741,824 bytes | 1024 Mega Bytes | One billion bytes
GDP
Gateway Discovery Protocol - Cisco ¨
A Cisco ¨ protocol that enables a router to dynamically learn about routes to other networks.
GFC
Generic Flow Control.
The first four bits of an ATM cell header. Manages traffic flow to the ATM network by controlling the user-network interface.
GGP
Gateway-To-Gateway Protocol - ARPA / Dod. The protocol core gateways used to exchange routing information, implementing a distributed shortest path routing GSM/EDGE Radio Access Network computation.
GGSN
Gateway GPRS Support Node
GMII
Gigabit Media Independent Interface.
A standardized interface within the 802.3 Gigabit Ethernet standard.
GPRS
General Packet Radio Service.
Up to 171 Kbit/s - but will be 1st used at 30 then 100 Kbit/s see also packet switching
GQS
Guaranteed Quality Service - IETF
GRE
Generic Routing Encapsulation.
RFC 2784. A protocol providing data encapsulation to allow tunneling.
Tunnels provide a specific pathway across the shared WAN and encapsulate traffic with new packet headers to ensure delivery to specific destinations.
The network is private because traffic can enter a tunnel only at an endpoint. Tunnels do not provide true confidentiality (encryption does) but can carry encrypted traffic.
GRE Tunneling can also be used to encapsulate non-IP traffic into IP and send it over the Internet or IP network. The Internet Package Exchange (IPX) and AppleTalk protocols are examples of non-IP traffic.
Group 3
Standard created by the International Telecommunication Union Telecommunications relating to Fax devices. A Group 3 fax device is a digital machine containing a 14400 baud modem that can send an 8 1/2 by 11-inch page in approximately 20 seconds with a resolution of either 203 by 98 dots per inch or 203 by 196 dpi - fine - using Huffman code to compress fax data. Group 3 faxes use a standard dial up telephone line for transmission.
GTP
GPRS Tunnel Protocol - Protocol above TCP/IP or UDP/IP allows PDU/PDP encapsulation on an IP datagram.
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