S-Access ETHERLINK IV Technical Description And Operations Manual
                                                                                                           | |
Contents
| 
DT Etherlink IV User Manual- 27 -3.2.2.3.2 Automatic V.54 LoopsThe system supports only a local V.54 loop managed by the line 141. The support of the V.54 loopsis software programmable. You can use the command AUTOLOOP to adjust automatic loopreaction: Lines 140 and 142 are not supported by the system.3.2.2.4 Ethernet InterfaceThe Ethernet interfaces of all S-Access Etherlink_IV devices fulfil the standard IEEE 802.3 andsupport the Port (PBVLAN command) and Tag (VLAN command) based VLAN protocol (VirtualLocal Area Network – IEEE 802.1Q). A virtual network represents a group of network nodes, whosetraffic, including the broadcast traffic, is completely isolated from other network nodes. Theorganization of virtual networks usually decreases the load in the network, because the broadcasttraffic will be transmitted not to the entire network but to members of the VLAN sender. Due to thefact that the members of different VLANs can exchange information via a router, which allows acontrolled traffic, the use of VLAN technology provides a high level of security. In addition, anychanges in the network structure are simplified because instead of configuring the work station towhich the modem is connected you only have to configure the modem port.To construct VLAN networks and to provide the priority in the data transmission, an extendedEthernet frame is used, which contains an additional VLAN tag of 2 bytes length. The tag includesthe number of the VLAN to which the packet belongs and its priority level.Some types of traffic (real-time video, voice or IP traffic) should be sent inside the network withoutany delays. To provide the necessary quality of this traffic, the Etherlink_IV devices support Ethernettraffic priority according to the standard protocol IEEE 802.1P (so-called QoS, Quality of Service). Itmeans to analyze the header content of each Ethernet frame to get information about the necessarypriority of this application. The internal switch places this data to the corresponding queue of theoutput port. The Etherlink_IV equipment supports two priority queues when sending packets – ahigh and low priority queue. According to it, all Ethernet traffic can be divided into high prioritygroups (for example VoIP traffic or control and management channels) and low priority groups (forexample LAN1 and LAN2).The Ethernet traffic between all network interfaces of the device is distributed by the internalEthernet switch (see next figure). In Etherlink_IV devices four types of network interfaces exist: Ethernet interfaces (external connector on the front panel, and back plane connector) SHDSL interfaces (when the device is properly configured) E1 interfaces (when the device is properly configured) Virtual management port (Telnet session)The number of E1 and SHDSL interfaces depends on the model of the Etherlink_IV family. Thechoice of the interface (DSL or E1), which will be mapped to the corresponding WAN interface isperformed by the |
This manual is suitable for:
manualsdatabase
Your AI-powered manual search engine