问答题
以下是使用E1线路实现多个64Kbit/s专线连接。
当链路为T1时,channel-group编号为0~23,Timeslot范围为1~24;当链路为E1时, channel-group编号为0~30,Timeslot范围为1~31。
路由器具体设置如下:
Current configuration:
version 11.2
no service udp-small-servers
no service tcp-small-servers
!
hostname router1
!
enable secret 5 $ 1 $ XN08 $ Ttr8nfLoP9.2RgZhcBzkk/
enable password cisco
!
!
ip subnet-zero
controller E1 0
{{U}}framing NO-CRC4{{/U}}
{{U}}channel-group 0 timeslots 1{{/U}}
{{U}}channel-group 1 timeslots 2{{/U}}
{{U}}channel-group 2 timeslots 3{{/U}}
!
interface Ethernet0
ip address 133.118.40.1 255.255.0.0
media-type 10BaseT
interface Ethernet1
no ip address
shutdown
{{U}}interface Serial0:0{{/U}}
ip address 202.119.96.1 255.255.255.252
encapsulation hdlc
no ip mroute-Cache
interface Serial0:1
ip address 202.119.96.5 255.255.255.252
encapsulation hdlc
no ip mroute-Cache
!
interface Serial0:2
ip address 202.119.96.9 255.255.255.252
encapsulation hdlc
no ip mroute-Cache
no ip classless
ip route 133.210.40.0 255.255.255.0 Serial0:0
ip route 133.210.41.0 255.255.255.0 Serial0:1
ip route 133.210.42.0 255.255.255.0 Serial0:2
line con 0
line aux 0
line vty 0 4
password cicso
Iogin
!
end
问答题
E1和CE1的主要区别是什么?
【正确答案】
【答案解析】CEl的传输线路的带宽是2048 Kbit/s,它和E1的区别主要在于:E1不能划分时隙,CEl能划分时隙。CEl的每个时隙是 64Kbit/s,一共有32个时隙,在使用的时候,可以划分为n×64Kbit/s,例如:128 Kbit/s,256 Kbit/s等。CE1的0和15时隙是不用来传输用户的数据流量,0时隙是传送同步号,15时隙传送控制信令,这样实际能用的只有30个时隙,所以在具体配置CE1划分时隙时,需要注意。CE1和E1也可以互联,但是CE1必须当K1来使用,即不可分时隙使用。因为CE1比较灵活,所以我们能常常碰到CE1。
问答题
解释配置中画线部分内容含义。
【正确答案】
【答案解析】Current configuration: ! version 11.2 no service udp-small-servers no service tcp-small-servers hostname router1 ! enable secret 5 $ 1 $ XN08 $ Ttr8nfLoP9.2RgZhcBzkk/ enable password cisco ! ip subnet-zero ! controller E1 0 framing NO-CRC4 //帧类型为no-crc4 channel-group 0 timeslots 1 //建立逻辑通道组0与时隙1的映射 channel-group 1 timeslots 2 //建立逻辑通道组1与时隙2的映射 channel-group 2 timeslots 3 //建立逻辑通道组2与时隙3的映射 interface Ethernet0 ip address 133.118.40.1 255.255.0.0 media-type 10BaseT ! interface Ethernet1 no ip address shutdown ! interface Serial0:0 //逻辑接口 Serial0:0 ip address 202.119.96.1 255.255.255.252 encapsulation hdlc no ip mroute-cache interface Serial0:1 ip address 202.119.96.5 255.255.255.252 encapsulation hdlc no ip mroute-cache ! interface Serial0:2 ip address 202.119.96.9 255.255.255.252 encapsulation hdlc no ip mroute-cache no ip classless ip route 133.210.40.0 255.255.255.0 Serial0:0 ip route 133.210.41.0 255.255.255.0 Serial0:1 ip route 133.210.42.0 255.255.255.0 Serial0:2 line eon 0 line aux 0 line vty 0 4 password cicso login end