Configuring Physical Layer Interfaces
The system supports a number of line rates; some of these are listed per line module below.
- E3 line module and COCX-F3 line module support
unchannelized E3. - CE1 module supports E1 and fractional E1.
- Channelized OCx/STMx (cOCx/STMx) line module supports DS3 channelized to DS1, fractional DS1, or the DS0 level; unchannelized DS3; E1/T1 channelized to fractional DS1; unframed E1.
- CT1 line module supports T1 and fractional T1.
- CT3 and CT3 12-FO line modules support DS3 channelized to DS1, fractional DS1, or the DS0 level. CT3 12-FO line modules also support unchannelized T3.
- FE-2 line module supports Fast Ethernet.
- HSSI line module supports high-speed serial interfaces.
- IPSec Service module provides tunnel service for secure tunnels.
- GE/FE line module supports Gigabit Ethernet and Fast Ethernet.
- OCx/STMx ATM line module supports OC3/STM1 ATM, OC12/STM4 ATM and unchannelized T3.
- OCx/STMx POS line module supports OC3/STM1 POS and OC12/STM4 POS.
- OC48 line module supports OC48/STM16 POS.
- T3 line module and COCX-F3 line module support
unchannelized T3. - TSM provides tunnel service for IP tunnels and LNS termination.
- X.21/V.35 line module supports X.21/V.35 serial interfaces.
A variety of protocols are supported over these interfaces, including IP/Frame Relay, IP/ATM, IP/PPP, as well as the protocols to enable B-RAS services. The system's DSx and E1/E3 implementations support termination, statistics gathering, alarm surveillance, and performance monitoring. These links can be used for either network ingress or network egress.
As shown in Figure 1-4, the system can support fractional, full, and channelized interfaces.
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Line Module Features
The following features are supported by the system line modules:
- Three different clocking options: internal timing, loop timing, and chassis timing
- DS3 framing type - both M23 framing and C-bit parity
- DS1 framing type - both D4 framing mode and ESF framing mode
- DS3 loopback - for line, payload, diagnostic, and DS1 loopbacks (see Diagnostics in ERX Product Overview Guide, Chapter 9, Statistics, Accounting, and Diagnostics, for more information)
- DS1 loopback - for line, payload, and diagnostic loopbacks (see Diagnostics in ERX Product Overview Guide, Chapter 9, Statistics, Accounting, and Diagnostics, for more information)
- DS3/DS1 line status/alarm monitoring
- DS1 line coding type - both AMI line encoding and B8ZS line encoding
- Unique IP interface support - for each PPP or Frame Relay PVC interface
Configurable HDLC Parameters
The following HDLC parameters are configurable:
- Mapping of DS0 timeslots for T1/FT1 DS0 mapping
- Setting the speed of the DS0 to Nx56 or Nx64
- HDLC CRC checking (enable/disable)
- HDLC CRC algorithm (CRC16 or CRC32)
- Channel data inversion (enable/disable)
- Maximum receive unit (MRU)
- Maximum transmit unit (MTU)
Statistics are also gathered per line module.
Configuring CT3 Interfaces
There are three T3 controllers available on each CT3 line module and 12 T3 controllers available on each CT3 12-FO line module. When you configure these T3 controllers, you are actually configuring T3 (DS3) lines. Each T3 controller has, by definition, 28 T1 controllers representing T1 (DS1) lines.
Use the T3 and T1 commands described in ERX Physical Layer Configuration Guide, Chapter 1, Configuring Channelized T3 Interfaces, to:
- Specify the line characteristics, such as framing format and clock source, for T3s and associated T1s.
- Assign full and fractional T1 channels (DS0) to a virtual channel.
Figure 1-5 shows sample parameters for a CT3 interface configuration.
The following sample command sequence configures a serial interface for a CT3 module. See ERX Physical Layer Configuration Guide, Chapter 1, Configuring Channelized T3 Interfaces, for details.
host1(config)#controller t3 0/1
host1(config-controll)#framing c-bit
host1(config-controll)#clock source line
host1(config-controll)#cablelength 220
host1(config-controll)#t1 2/1
host1(config-controll)#t1 2 framing esf
host1(config-controll)#t1 lineCoding b8zs
host1(config-controll)#t1 timeslots 2/1 1,3-8,10-12
host1(config-controll)#interface serial 0/1:2/1
Configuring T3 and E3 Interfaces
The T3 and E3 line modules support the following wide-area network (WAN) protocol encapsulations:
The T3 and E3 modules support the following WAN protocol encapsulations:
Figure 1-6 shows sample configuration parameters for a T3 interface configuration.
The following sample command sequence configures a serial interface for a T3 module. See ERX Physical Layer Configuration Guide, Chapter 2, Configuring T3 and E3 Interfaces, for details.
host1(config)#controller t3 0/1
host1(config-controll)#framing m23
host1(config-controll)#cablelength 300
host1(config-if)#ds3-scramble
host1(config)#interface serial 0/1
host1(config-if)#invert data
host1(config-if)#mtu 1600
host1(config-if)#mru 1600
Configuring CT1 and CE1 Line Interfaces
Figure 1-7 shows the configuration parameters for a sample T1 interface configuration on a CT1 line module.
The following sample command sequence configures a serial interface for a T1 module. See ERX Physical Layer Configuration Guide, Chapter 3, Configuring CT1 and CE1 Interfaces, for details.
host1(config)#controller t1 0/1
host1(config-controll)#channel group 2 timeslots 1,3-8,10
host1(config-controll)#framing sf
host1(config-controll)#lineCoding ami
host1(config-controll)#cablength short 200
host1(config-controll)#channel-group 2 trap link-status
host1(config)#interface serial 0/1:2
host1(config-controll)#crc 32
host1(config-if)#invert data
host1(config-if)#mtu 1600
host1(config-if)#mru 1600
Configuring OCx/STMx and OC48 Interfaces
The system supports IP/ATM and IP/PPP over SONET on the OCx/STMx interfaces. OC48 interfaces support IP/PPP over SONET, and do not support ATM operation. This interface support allows service providers to accept incoming optical connections or connect the system to the backbone network through optical connections. The system's SONET implementation supports termination, statistic gathering, and alarm surveillance at the section, line, and path layers of a SONET interface.
The following sample command sequence configures POS for an OC3 interface. See ERX Link Layer Configuration Guide, Chapter 5, Configuring Packet over SONET, for details.
host1(config)#interface pos 0/1
host1(config-if)#encapsulation ppp
host1(config-controll)#clock source internal module
host1(config-controll)#loopback line
host1(config-controll)#pos framing sdh
host1(config-controll)#mtu 1600
host1(config-controll)#mru 1600
host1(config-controll)#pos scramble-atm
Configuring Channelized OCx/STMx Line Interfaces
The cOCx/STMx modules are generally used for circuit aggregration on the system. This line module supports the following controllers over OC3/STM1 or OC12/STM4, depending on the I/O module used with the line module:
Figure 1-9 shows the configuration parameters for a sample T1 over DS3 interface configuration.
The following sample command sequence configures T1 over DS3 on a channelized SONET interface. See ERX Physical Layer Configuration Guide, Chapter 5, Configuring Channelized OCx/STMx Interfaces, for details.
host1(config)#controller sonet 3/0
host1(config-controller)#path 12 oc1 4/1
host1(config-controller)#path 12 ds3 1 channelized
host1(config-controller)#path 12 ds3 1 t1 4
host1(config-controller)#path 12 ds3 1 t1 4/2 timeslots 1, 3-8, 10-12
host1(config)#interface serial 3/0:12/1/4/2
Configuring Ethernet Interfaces
Ethernet interfaces support IP, PPPoE, multinetting (multiple IP addresses), and VLANs (subinterfaces). Ethernet modules use the Address Resolution Protocol (ARP) to obtain MAC addresses for outgoing Ethernet frames and support quality of service (QoS) classification. See ERX Physical Layer Configuration Guide, Chapter 6, Configuring Ethernet Interfaces, for a description of limitations for individual modules.
Use the FE and GE commands described in Chapter 6, Configuring Ethernet Interfaces to:
- Configure with IP only, with PPPoE only, with both IP and PPPoE, and with or without VLANs.
- Specify the line speed and duplex mode.
- Specify the MTU.
- Set the time interval at which the ERX system calculates bit and packet rate counters.
The following sample command sequence configures an IP interface on a VLAN on an Ethernet interface:
host1(config)#interface fastethernet 2/0.1
host1(config-if)#vlan id 100
host1(config-if)#interface fastethernet 2/0.1.1
host1(config-if)#ip address 192.1.1.1 255.255.255.0
The following sample command sequence adds an IP interface over PPPoE to the same VLAN:
host1(config)#interface fastethernet 2/0.1.2
host1(config-if)#encapsulation pppoe
host1(config-if)#interface fastethernet 2/0.1.2.1
host1(config)#encapsulation ppp
host1(config-if)#ip address 192.2.2.1 255.255.255.0
Configuring HSSI Interfaces
High-speed serial interfaces (HSSIs) support high-speed WAN switching services such as Frame Relay and SMDS (SMDS trunk encapsulation). You can configure an interface to act as data communication equipment (DCE) or data terminal equipment (DTE).
Figure 1-10 shows sample configuration parameters for a HSSI configuration.
The following sample configuration shows how to use the HSSI as a DTE. See ERX Physical Layer Configuration Guide, Chapter 7, Configuring HSSIs, for details.
host1(config)#interface hssi 3/0
host1(config-if)#crc 32
host1(config-if)#mtu 1200
host1(config-if)#snmp trap link-status
Configuring X.21/V.35 Interfaces
X.21/V.35 interfaces are serial interfaces that support the following:
- Data communications equipment (DCE) or data terminal equipment (DTE) operation
- Maximum data rate of 10 Mbps per port, 50 Mbps across all ports
Figure 1-11 shows sample configuration parameters for an X.21/V.35 interface configuration.
The following example shows how to configure the X.21/V.35 interface as a DCE. See ERX Physical Layer Configuration Guide, Chapter 8, Configuring X.21/V.35 Interfaces, for details.
host1(config)#interface serial 3/1
host1(config-if)#clock rate 1536000
host1(config-if)#crc 32
host1(config-if)#mtu 1200
host1(config-if)#nrzi-encoding
Configuring IPSec Service Interfaces
IPSec Service modules support interfaces associated with secure IP tunnels. You configure and delete these interfaces statically; however, the system assigns tunnels to the interfaces dynamically. This mechanism means that you must manage the interfaces for tunnels manually; however, the system will add and remove tunnels when required.
For information on configuring secure IP interfaces, see ERX Routing Protocols Configuration Guide, Vol. 1, Chapter 11, Configuring IPSec. For information about managing IPSec service interfaces, see ERX Physical Layer Configuration Guide, Chapter 9, Managing Tunnel Service and IPSec Service Interfaces.
Configuring TSM Interfaces
You can configure both dynamic tunnels associated with L2TP and static IP tunnels on your ERX system; however, you must first install a TSM. Dynamic tunnels, which are not associated with a particular interface, are described in ERX Broadband Access Configuration Guide, Chapter 5, Configuring L2TP. Static tunnels, in which the tunnel is assigned to a particular interface and specified in slot/port format, are described in ERX Routing Protocols Configuration Guide, Vol. 1, Chapter 5, Configuring IP Tunnels.
For information about managing these types of tunnels on the system, see ERX Physical Layer Configuration Guide, Chapter 9, Managing Tunnel Service and IPSec Service Interfaces.