DDN设置
DDN(Digital Data Network)是一种点对点的同步数据通信链路.它支持PPP,SLIP,HDLC和SDLC等链路层通信协议.允许IP,Novell IPX, Bridging,CLNS,AppleTalk,DECnet等多种上层协议在上面运行.
基本配置
压缩技术
E1端口配置
基本配置
功 能 命 令
进入指定端口 interface serial number
定义该端口IP地址 ip address ip-address mask
指定该端口打包方式 encapsulation {PPP|HDLC }
压缩技术
通常在串口中传输的数据是不压缩的,它允许数据包头在每次传输时正常交换,但每次将浪费带宽.目前支持的压缩有PPP,FrameRelay, X.25, TCP等等.
Cisco的压缩是通过软件完成的,将影响系统性能.故建议路由器CPU占用超过65%,就不要使用压缩.(showprocess cpu EXEC命令查看当前CPU使用情况)
功 能 命 令
TCP传输头压缩 ip tcp head-compression [passive]
X.25压缩 X25 compress
PPP压缩 ppp compress [predictir|stac]
注:"passive"表示只有输入包是压缩时,输出包才压缩.
E1端口配置
在Cisco 4500,4700,7000和7500系列里面均支持E1(2.048Mbps)数率的接口.每一个E1端口可以按时隙分成30路64K数据线路和2路信号线路.这30个64K数据线路每一路均可以当作一条64K的专线.
功 能 命 令
在配置模式下,定义Controller E1 controller e1 slot/port
定义line code linecode {ami |hdb3}
定义字符帧 framing {crc4 |no-crc4}
定义E1组 channel-group numbertimeslots range [speed{48| 56|64}]
指定串口属于那一个channel-group组 interface serial
slot/port:channel-group
注:
slot/port----是针对7000或7500系列的,故区分槽口号和端口号.
linecode----默认是HDB3.
framing----默认是crc4,要与电信局参数匹配.
channel-group----每个E1可以分成30个channel-group,把channel-group和时间槽对应起来.channel-group是0-30,timeslots是1-31.
interface serial----在定义完E1 channel-group后,我们把group赋予成一个虚拟串口
3. 举例使用E1线路实现多个64K专线连接.
相关命令:
任务 命令
进入controller配置模式 controller {t1 | e1} number
选择帧类型 framing {crc4 | no-crc4}
选择line-code类型 linecode {ami | b8zs | hdb3}
建立逻辑通道组与时隙的映射 channel-group number timeslots range1
显示controllers接口状态 show controllers e1 [slot/port]2
注: 1. 当链路为T1时,channel-group编号为0-23, Timeslot范围1-24; 当链路为E1时, channel-group编号为0-30, Timeslot范围1-31.
2.使用show controllers e1观察controller状态,以下为帧类型为crc4时controllers正常的状态.
Router# show controllers e1
e1 0/0 is up.
Applique type is Channelized E1 - unbalanced
Framing is CRC4, Line Code is HDB3 No alarms detected.
Data in current interval (725 seconds elapsed):
0 Line Code Violations, 0 Path Code Violations
0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
Total Data (last 24 hours) 0 Line Code Violations, 0 Path Code Violations,
0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,
0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
以下例子为E1连接3条64K专线, 帧类型为NO-CRC4,非平衡链路,路由器具体设置如下:
shanxi#wri t
Building configuration...
Current configuration:
!
version 11.2
no service udp-small-servers
no service tcp-small-servers
!
hostname shanxi
!
enable secret 5 $1$XN08$Ttr8nfLoP9.2RgZhcBzkk/
enable password shanxi
!
!
ip subnet-zero
!
controller E1 0
framing NO-CRC4
channel-group 0 timeslots 1
channel-group 1 timeslots 2
channel-group 2 timeslots 3
!
interface Ethernet0
ip address YYY.118.40.1 255.255.0.0
media-type 10BaseT
!
interface Ethernet1
no ip address
shutdown
!
interface Serial0:0
ip address TTT.119.96.1 255.255.255.252
no ip mroute-cache
!
interface Serial0:1
ip address TTT.119.96.5 255.255.255.252
no ip mroute-cache
!
interface Serial0:2
ip address TTT.119.96.9 255.255.255.252
no ip mroute-cache
!
no ip classless
ip route YYY.210.40.0 255.255.255.0 Serial0:0
ip route YYY.210.41.0 255.255.255.0 Serial0:1
ip route YYY.210.42.0 255.255.255.0 Serial0:2
!
line con 0
line aux 0
line vty 0 4
password shanxi
login
!
end
