D-Link DAS-3224_revB User Manual
DAS3 Series Operation Menus
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4.3 Configuration
Configuration menu contains setting for VPI/VCI, ADSL Line profile, alarm profile, power
management profile, as well as VLAN, MAC, IGMP, Spanning Tree Protocol, Bridge Information, and
DHCP configuration.
management profile, as well as VLAN, MAC, IGMP, Spanning Tree Protocol, Bridge Information, and
DHCP configuration.
4.3.1 VPI/VCI
VPI/VCI configuration allows operator to add PVC for the network element. Figure 4-10 shows the
window to add VPI/VCI.
ATM (Asynchronous Transfer Mode) is more efficient than synchronous technologies like
time-division multiplexing (TDM). With TDM, each station or users is pre-assigned some time slots,
and no other station can send in that time slot. With ATM being asynchronous in nature, time slots are
available on demand.
ATM supports integrated voice, data, and video communications. In ATM the information to be
transmitted in divided into short 53 byte packets or cells, which have a 5 byte header. The reason for
such a short cell length is that ATM must deliver real time service at low bit rates and thus it
minimizes packetization delay. ATM networks are connection oriented with virtual channels and
virtual paths. The virtual channel carries one connection while a virtual path may carry a group of
virtual channels. This ensures that cell sequence is maintained throughout the network. The virtual
channel is identified by the Virtual Channel Identifier, (VCI), and the virtual path is identified by the
Virtual Path Identifier, (VPI). Both the VCI and VPI may change within the network and they are
stored in the header of the cell.
AAL (ATM Adaptation Layer) makes the ATM layer services more adaptable to specific services. The
specific services may include user services, control services and management services. The AAL is the
layer above the ATM layer and it is responsible for converting the information from the higher layers
into 48 byte lengths so that the ATM layer can add the 5 byte header to make the 53 byte cell. The two
main functions of this AAL are to provide functions needed to support applications and to break up
information into units that will fit into cells. There are five AAL layers and each layers is loosely
associated with the class of traffic to be carried. AAL1 is designed to support constant bit rate,
connection oriented, and synchronous traffic such as uncompressed video transmission. AAL2 is never
completed, but it was envisioned to be assigned for variable bit rate, connection-oriented, synchronous
traffic. AAL3/4 supports variable bit rate, connection oriented, and asynchronous traffic or
connectionless packet data. AAL5 is the primary AAL for data and supports both connection oriented
and connectionless data.
window to add VPI/VCI.
ATM (Asynchronous Transfer Mode) is more efficient than synchronous technologies like
time-division multiplexing (TDM). With TDM, each station or users is pre-assigned some time slots,
and no other station can send in that time slot. With ATM being asynchronous in nature, time slots are
available on demand.
ATM supports integrated voice, data, and video communications. In ATM the information to be
transmitted in divided into short 53 byte packets or cells, which have a 5 byte header. The reason for
such a short cell length is that ATM must deliver real time service at low bit rates and thus it
minimizes packetization delay. ATM networks are connection oriented with virtual channels and
virtual paths. The virtual channel carries one connection while a virtual path may carry a group of
virtual channels. This ensures that cell sequence is maintained throughout the network. The virtual
channel is identified by the Virtual Channel Identifier, (VCI), and the virtual path is identified by the
Virtual Path Identifier, (VPI). Both the VCI and VPI may change within the network and they are
stored in the header of the cell.
AAL (ATM Adaptation Layer) makes the ATM layer services more adaptable to specific services. The
specific services may include user services, control services and management services. The AAL is the
layer above the ATM layer and it is responsible for converting the information from the higher layers
into 48 byte lengths so that the ATM layer can add the 5 byte header to make the 53 byte cell. The two
main functions of this AAL are to provide functions needed to support applications and to break up
information into units that will fit into cells. There are five AAL layers and each layers is loosely
associated with the class of traffic to be carried. AAL1 is designed to support constant bit rate,
connection oriented, and synchronous traffic such as uncompressed video transmission. AAL2 is never
completed, but it was envisioned to be assigned for variable bit rate, connection-oriented, synchronous
traffic. AAL3/4 supports variable bit rate, connection oriented, and asynchronous traffic or
connectionless packet data. AAL5 is the primary AAL for data and supports both connection oriented
and connectionless data.
AMS
Software Specification and Introduction Guide
Software Specification and Introduction Guide