H3C S9500 Series User manual

Operation Manual – POS Interface
H3C S9500 Series Routing Switches Table of Contents
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Table of Contents
Chapter 1 POS Interface Configuration.......................................................................................1-1
1.1 Overview............................................................................................................................1-1
1.1.1 SONET/SDH ...........................................................................................................1-1
1.1.2 POS.........................................................................................................................1-1
1.2 Configuring a POS Interface..............................................................................................1-1
1.3 Displaying and Maintaining POS Interfaces......................................................................1-3
1.4 POS Interface Configuration Example...............................................................................1-3
1.4.1 Network Requirements............................................................................................1-3
1.4.2 Network Diagram.....................................................................................................1-4
1.4.3 Configuration procedure..........................................................................................1-4
1.5 Troubleshooting POS Interfaces........................................................................................ 1-4

Operation Manual – POS Interface
H3C S9500 Series Routing Switches Chapter 1 POS Interface Configuration
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Chapter 1 POS Interface Configuration
When configuring a POS interface, go to these sections for information you are
interested in:
zOverview
zConfiguring a POS Interface
zDisplaying and Maintaining POS Interfaces
zPOS Interface Configuration Example
zTroubleshooting POS Interfaces
1.1 Overview
1.1.1 SONET/SDH
Synchronous optical network (SONET), a synchronous transmission system defined by
ANSI, is an international standard transmission protocol. It adopts optical transmission.
Synchronous digital hierarchy (SDH) was defined by CCITT (today’s ITU-T). It uses
synchronous multiplexing and flexible mapping to add/drop low-speed tributary signals
from SDH signals directly, without using multiple multiplexing/demultiplexing devices,
thus reducing signal loss and investment in devices.
1.1.2 POS
Packet over SONET/SDH (POS) is a technology popular in WAN and MAN. POS maps
length-variable packets directly to SONET synchronous payloads and uses the SONET
physical layer transmission standard. It offers high-speed, reliable, and point-to-point
data connectivity. It can support packet-switched data such as IP packets.
The POS interface on your device supports PPP, Frame Relay, and HDLC at the data
link layer and IP at the network layer. The rate of POS interfaces may be different
depending on your device. The rate can be STM-1 (155 Mbps), STM-4c (622 Mbps),
and STM-16c/STM-16 (2.5 Gbps), each four times the immediate lower level.
1.2 Configuring a POS Interface
Before you configure the link layer andnetwork layer protocols on a POS interface, you
must configure its physical parameters. In addition, to have the interface participate in
backup, configure the backup parameters; to set up firewall on the interface, configure
packet-filtering rules.
Follow these steps to configure a POS interface:

Operation Manual – POS Interface
H3C S9500 Series Routing Switches Chapter 1 POS Interface Configuration
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To do... Use the command... Remarks
Enter system view system-view ––
Enter POS interface view interface pos
interface-number Required
Set the clock mode clock { master | slave } Optional
The default is slave.
Set the CRC length crc { 16 | 32 } Optional
The default is 32 bits.
Set the loopback mode loopback { local |
remote } Optional
Disabled by default
Configure the overhead
byte flag { c2 | { j0 | j1 } { sdh | sonet } } flag-value
Optional
By default, SDH framing
applies.
The default is
hexadecimal 16 for C2.
In SDH framing, the
defaults are 15 0x0 for
both J0 and J1.
In SONET framing, the
defaults are 0x01 for J0
and 62 0x0 for J1.
Set the framing format frame-format { sdh |
sonet } Optional
The default is SDH.
Configure scrambling scramble Optional
Enabled by default.
Set the link protocol type link-protocol ppp Optional
The default is PPP.
Set the PPP negotiation
timeout time ppp timer negotiate
seconds Optional
The default is 3 seconds.
Set the interval to send
keepalive packets timer hold seconds Optional
The default is 10 seconds.
Set the interface MTU mtu size Optional
The default is 1,500 bytes.
Set the SD/SF threshold
for the interface threshold { sd | sf } value
Optional
The SD threshold defaults
to 10e-6. The SF
threshold defaults to
10e-3.

Operation Manual – POS Interface
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To do... Use the command... Remarks
Shut down the POS
interface shutdown Optional
POS interfaces are
enabled by default.
Note:
zAt present, POS interfaces on S9500 series routing switches only support PPP on
data link layer.
zCurrently, POS interfaces on S9500 series routing switches do not support IPv6
multicast. Therefore, the commands related to IPv6 multicast are not supported in
POS interface view.
zOn PPP links, as IPv6CP cannot obtain the peer IPv6 addresses through
negotiation, static routes or routing protocols are required to achieve hardware IPv6
forwarding on POS interfaces.
zIf a physical interface is idle or has no cable connection, shut down it with the
shutdown command to avoid interface anomalies that may result from interference.
zAs the shutdown command disables an interface, use the command with caution.
1.3 Displaying and Maintaining POS Interfaces
To do... Use the command... Remarks
Display the information of a POS
interface display interface pos [ interface-number ]
Display the IP-related
information of a POS interface display ip interface pos
interface-number
Display the IPv6-related
information of a POS interface display ipv6 interface pos
interface-number
Available in any
view
1.4 POS Interface Configuration Example
1.4.1 Network Requirements
Use a pair of optic fibers (respectively for receiving and sending data) to connect the
POS interfaces on SwitchA and Switch B.
Encapsulate the interfaces with PPP.

Operation Manual – POS Interface
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1.4.2 Network Diagram
Switch A Switch B
POS1/1/1
10.110.1.10/24 POS4/1/1 10.110.1.11/24
Figure 1-1 Network diagram for connecting two POS interfaces through fiber
1.4.3 Configuration procedure
1) Configure Switch A
# Configure interface POS 1/1/1, setting all its physical parameters to the defaults.
<SwitchA> system-view
System View: return to User View with Ctrl+Z
[SwitchA] interface pos 1/1/1
[SwitchA-Pos1/1/1] ip address 10.110.1.10 255.255.255.0
[SwitchA-Pos1/1/1] link-protocol ppp
[SwitchA-Pos1/1/1] mtu 1500
[SwitchA-Pos1/1/1] shutdown
[SwitchA-Pos1/1/1] undo shutdown
2) Configure Switch B
# Configure interface POS 4/1/1.
<SwitchB> system-view
System View: return to User View with Ctrl+Z
[SwitchB] interface pos 4/1/1
# Set the clock mode to master and other physical parameters to the defaults.
[SwitchB-Pos4/1/1] clock master
[SwitchB-Pos4/1/1] ip address 10.110.1.11 255.255.255.0
[SwitchB-Pos4/1/1] link-protocol ppp
[SwitchB-Pos4/1/1] mtu 1500
[SwitchB-Pos4/1/1] shutdown
[SwitchB-Pos4/1/1] undo shutdown
You can check the interface connectivity between the POS interfaces with the display
interface pos command and test network connectivity with the ping command.
1.5 Troubleshooting POS Interfaces
Symptom 1:
The physical state of the POS interface is down.

Operation Manual – POS Interface
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Solution:
zCheck that the transmitting and receiving fibers-optic are correctly connected to
the POS interface. If you connect the two ends of a fiber-optic to the transmitting
end and the receiving end of the same POS interface, you can see the message
“loopback detected” on the screen when executing the display interface
command even if you have not enabled loopback.
zIf your switch is connected to another switch directly, check that the clock mode of
the local POS interface is opposite to that on the connected POS interface.
Symptom 2: The physical layer is up but the link layer is down.
Solution:
Check that:
zThe configurations of clock, scrambling and other physical interfaces are
consistent on the two sides.
zThe same link layer protocol is configured on two sides.
zBoth ends are assigned IP addresses.
Symptom 3:
A great amount of IP packets are dropped.
Solution:
Check that:
zThe correct clock mode is configured on the POS interface. If not, enormous
amount of CRC errors can be generated.
zCheck that the MTU configuration is appropriate.