80 CHAPTER 1: ATM AND DSL INTERFACE CONFIGURATIONn When executing the bootrom update file command, do not use the all optionunless absolutely necessary; use the part option instead. If you use the all option,you will find it hard to roll back to the old version once the upgrade fails.G.SHDSL InterfaceConfigurationThis section covers these topics:■ “Overview” on page 72■ “Configuring a G.SHDSL Interface” on page 80Overview G. single-pair high-speed digital subscriber line (G.SHDSL) is a symmetrictransmission technology that implements high-speed data transmission over thetwisted-pair copper wire by making use of the unused high frequency ranges withdifferent modulation methods. So far, two types of G.SHDSL are supported:two-wire and four-wire. Two-wire G.SHDSL can provide transmission rates up to2.312 Mbps while four-wire G.SHDSL can provide transmission rates up to 4.624Mbps.The transmission speed of G.SHDSL is susceptible to transmission distance and linequality. While increased transmission distance means decreased line quality andtransmission rate, decreased transmission distance means the contrary. Whensetting up a link, G. SHDSL can automatically make tuning for a reasonable speedtaking into consideration the actual line conditions such as distance and noise.For the networking topology for the routers with G.SHDSL interfaces, refer to thatfor the routers with ADSL interfaces. But note that G.SHDSL interface requires nosplitter.For a typical network topology for routers with G.SHDSL interfaces, see Figure 2.You should note that unlike ADSL, G.SHDSL does not use the splitter.This section covers only the physical configurations of the G.SHDSL interface. Formore information about how to configure ATM (including PVCs), refer to “ATMConfiguration” on page 127.Configuring a G.SHDSLInterfaceFollow these steps to configure a G.SHDSL interface:To do... Use the command... RemarksEnter system view system-view --Enter ATM interface view interface atminterface-numberRequiredActivate the G.SHDSLinterfaceactivate OptionalThe interface is active by default.Set the G.SHDSL interfacestandardshdsl annex { a | b } OptionalAnnex B is adopted by default.Set the wiring mode shdsl wire { 2 |4-auto-enhanced |4-enhanced | 4-standard }Optional4-enhanced mode by defaultThis command is available only ifthe interface supports four-wireG.SHDSL.
