- mGRE Tunnel Support over IPv6
- IP over IPv6 Tunnels
- Manually Configured IPv6 over IPv4 Tunnels
- Configuring Physical Interfaces
- Configuring Virtual Interfaces
- Implementing Tunnels
- Tunnel Route Selection
- MPLS VPN over mGRE
- IP Tunnel MIBs
- IF-MIBs
- Synchronous Ethernet (SyncE) ESMC and SSM
- 1+1 SR-APS Without Bridging
- IPv6 Rapid Deployment
- IPv6 Automatic 6to4 Tunnels
- IPv6 over IPv4 GRE Tunnels
- GRE IPv6 Tunnels
- ISATAP Tunnel Support for IPv6
- VRF-Aware Tunnels
- Ethernet over GRE Tunnels
- QoS on Ethernet over GRE Tunnels
- VRF-Aware IPv6 Rapid Deployment Tunnel
- IP Tunnel - GRE Key Entropy Support
- Finding Feature Information
- Prerequisites for Synchronous Ethernet (SyncE) ESMC and SSM
- Restrictions for Synchronous Ethernet (SyncE) ESMC and SSM
- Information About Synchronous Ethernet (SyncE) ESMC and SSM
- How to Configure Synchronous Ethernet (SyncE) ESMC and SSM
- Configuration Examples for Synchronous Ethernet (SyncE) ESMC and SSM
- Additional References
- Feature Information for Synchronous Ethernet (SyncE) ESMC and SSM
Synchronous Ethernet (SyncE) ESMC and SSM
This module describes Synchronization Status Message (SSM), Ethernet Synchronization Message Channel (ESMC), and generating the Simple Network Management Protocol (SNMP) traps on the SyncE feature.
With Ethernet equipment gradually replacing Synchronous Optical Networking (SONET) and Synchronous Digital Hierarchy (SDH) equipment in service-provider networks, frequency synchronization is required to provide high-quality clock synchronization over Ethernet ports.
Synchronous Ethernet (SyncE) provides the required synchronization at the physical level. In SyncE, Ethernet links are synchronized by timing their bit clocks from high-quality, stratum-1-traceable clock signals in the same manner as SONET/SDH. Operation messages maintain SyncE links and ensure that a node always derives timing from the most reliable source.
SyncE synchronizes clock frequency over an Ethernet port. In SONET/SDH the communication channel for conveying clock information is SSM, and in SyncE it is the ESMC.
- Finding Feature Information
- Prerequisites for Synchronous Ethernet (SyncE) ESMC and SSM
- Restrictions for Synchronous Ethernet (SyncE) ESMC and SSM
- Information About Synchronous Ethernet (SyncE) ESMC and SSM
- How to Configure Synchronous Ethernet (SyncE) ESMC and SSM
- Configuration Examples for Synchronous Ethernet (SyncE) ESMC and SSM
- Additional References
- Feature Information for Synchronous Ethernet (SyncE) ESMC and SSM
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for Synchronous Ethernet (SyncE) ESMC and SSM
You need to first configure the network clock for SyncE configuration. Automatic synchronization of the network clock should be enabled. Ensure that the network-clock-select and network-clock-participate commands do not exist in the configuration in order to continue with the SyncE configuration.
Restrictions for Synchronous Ethernet (SyncE) ESMC and SSM
The network-clock synchronization ssm option command cannot be used if the following parameters have been configured:
Note
After using the network-clock synchronization ssm option command, the restricted configurations listed above can be used.The network-clock synchronization ssm option command must be compatible with the network-clock eec command in the configuration.
The esmc process and synchronous mode commands can be used only if the SyncE capable interface is installed on the router.
Information About Synchronous Ethernet (SyncE) ESMC and SSM
Synchronous Ethernet (SyncE) ESMC and SSM
Customers using a packet network find it difficult to provide timing to multiple remote network elements (NEs) through an external time division multiplexed (TDM) circuit. The SyncE feature helps to overcome this problem by providing effective timing to the remote NEs through a packet network. SyncE leverages the physical layer of the Ethernet to transmit frequency to the remote sites. SyncE’s functionality and accuracy resemble the SONET/SDH network because of its physical layer characteristic. SyncE uses ESMC to allow the best clock source traceability to correctly define the timing source and help prevent a timing loop.
SONET/SDH use 4 bits from the two S bytes in the SONET/SDH overhead frame for message transmission. Ethernet relies on ESMC that is based on an IEEE 802.3 organization-specific slow protocol for message transmission. Each NE along the synchronization path supports SyncE, and SyncE effectively delivers frequency in the path. SyncE does not support relative time (for example, phase alignment) or absolute time (Time of Day).
SyncE provides the Ethernet physical layer network (ETY) level frequency distribution of known common precision frequency references. Clocks for use in SyncE are compatible with the clocks used in the SONET/SDH synchronization network. To achieve network synchronization, synchronization information is transmitted through the network via synchronous network connections with performance of egress clock. In SONET/SDH the communication channel for conveying clock information is Synchronization Status Message (SSM), and in SyncE it the Ethernet Synchronization Message Channel (ESMC).
ESMC carries a Quality Level (QL) identifier that identifies the timing quality of the synchronization trail. QL values in QL-TLV are the same as QL values defined for SONET and SDH SSM. Information provided by SSM QLs during the network transmission helps a node derive timing from the most reliable source and prevents timing loops. ESMC is used with the synchronization selection algorithms. Because Ethernet networks are not required to be synchronous on all links or in all locations, the ESMC channel provides this service. ESMC is composed of the standard Ethernet header for an organization-specific slow protocol; the ITU-T OUI, a specific ITU-T subtype; an ESMC-specific header; a flag field; and a type, length, value (TLV) structure. The use of flags and TLVs improves the management of SyncE links and the associated timing change. For details on Synchronous Ethernet support on Cisco 7600 series routers see Cisco 7600 Series Ethernet Services Plus (ES+) and Ethernet Services Plus T (ES+T) Line Card Configuration Guide .
How to Configure Synchronous Ethernet (SyncE) ESMC and SSM
Configuring SyncE
Perform this task to configure SyncE using ESMC and SSM.
1.
enable
2.
network-clock
set
l
ockout
{external slot / card / port[10m| 2m| t1{sf | esf | d4}] | interface type slot / port}
3.
network-clock
clear
lockout
{external slot / card / port [10m| 2m| t1 {sf | esf | d4}] | interface type slot / port}
4.
network-clock
switch
force
{
external
slot
/
card
/
port
[ 10m | 2m] | t0 | t1 {sf | esf | d4} t0 | internal { external slot / card / port[10m | 2m] | t0} | interface type slot / port external slot / card / port [ 10m | 2m] | t0 }
5.
network-clock
switch
manual
{
interface
type
slot
/port { external slot / card / port [10m | 2m ] | t0 } | external slot / card / port{10m | 2m | t0 | t1 {sf | esf | d4} | internal { external slot / card / port[10m | 2m] | t0} }
6.
network-clock
clear
switch
{t0 | external slot / card / port [10m | 2m]}
7.
configure
terminal
8.
network-clock
synchronization
automatic
9.
network-clock
synchronization
ssm
option
{1| 2{GEN1| GEN2}}
10.
network-clock
input-source
priority
{external slot / card / port [ 10m | 2m | t1 {sf | esf | d4}] | interface type slot / port}
11.
network-clock
synchronization
mode
ql-enabled
12.
network-clock
hold-off
{0| milliseconds}
13.
network-clock
wait-to-restore
seconds
14.
esmc
process
15.
network-clock
external
slot
/
card
/
port
hold-off
{0 | milliseconds}
16.
network-clock
quality-level
{tx| rx} value {interface type slot / port | external slot / card / port [10m | 2m | t1 {sf | esf | d4}]
17.
network-clock
output-source
{line
| system} priority interface type slot / port external slot / card / port[10m | 2m | t1{sf | esf | d4} ]
18.
interface
type
number
19.
synchronous
mode
20.
esmc
mode
[ql-disabled| tx| rx] value
21.
network-clock
source
quality-level
value
{tx | rx}
22.
network-clock
hold-off
{0 | milliseconds}
23.
network-clock
wait-to-restore
seconds
24.
end
DETAILED STEPS
Enabling and Disabling an SNMP Trap in the SyncE Event
A Simple Network Management Protocol (SNMP) trap is defined for an SNMP agent to notify the Network Management Systems (NMS) about any unsolicited information. The SNMP trap notifies NMS when a critical SyncE event occurs on a device. If the SNMP trap is enabled in the SyncE configuration, the SNMP agent code generates a SyncE trap for the SyncE events.
Perform the following tasks to enable and disable the SNMP trap for the SyncE event:
1.
enable
2.
configure
terminal
3.
snmp-server
enable
traps
netsync
4.
no
snmp-server
enable
traps
netsync
5.
end
6.
show
running-config
all
|
include
traps
DETAILED STEPS
Configuration Examples for Synchronous Ethernet (SyncE) ESMC and SSM
- Example Synchronous Ethernet (SyncE) ESMC and SSM
- Example Enabling and Disabling an SNMP Trap in the SyncE Event
Example Synchronous Ethernet (SyncE) ESMC and SSM
The following examples shows the SyncE configuration sequence (configuring an interface with two SyncE interfaces and two external interfaces):
Interface GigabitEthernet0/0/0 synchronous mode clock source line network-clock wait-to-restore 720 ! Interface GigabitEthernet1/0/0 synchronous mode clock source line ! network-clock synchronization automatic network-clock input-source 1 external 0/0/0 2m network-clock input-source 2 external 1/0/0 2m network-clock output-source line 1 interface GigabitEthernet0/0/0 external 0/0/0 2m network-clock output-source line 1 interface GigabitEthernet1/0/0 external 1/0/0 2m
The following examples shows how to verify whether ESMC is enabled or not:
Router# show esmc Interface: GigabitEthernet0/0/0 Administrative configurations: Mode: Synchronous ESMC TX: Enable ESMC RX : Enable QL RX configured : NA QL TX configured : NA Operational status: Port status: UP QL Receive: QL-SSU-B ESMC Information rate : 1 packet/second ESMC Expiry: 5 second
The following examples shows how to view the network clock synchronization details:
Router# show network-clock synchronization detail Automatic selection process : Enable Equipment Clock : 2048 (EEC-Option1) Clock Mode : QL-Enable ESMC : Disabled SSM Option : 1 T0 : Internal Hold-off (global) : 300 ms Wait-to-restore (global) : 300 sec Revertive : No Force Switch: FALSE Manual Switch: FALSE Number of synchronization sources: 1 Secondary src: Ethernet0/0 Slots disabled 0x0 Monitor source(s): Ethernet0/0 Selected QL: QL-SEC sm(netsync_ql_dis NETCLK_QL_ENABLE), running yes, state 1A Last transition recorded: (begin)-> 1A (ql_mode_enable)-> 1A (src_added)-> 1A Nominated Interfaces Interface SigType Mode/QL Prio QL_IN ESMC Tx ESMC Rx *Internal NA NA/Dis 251 QL-SEC NA NA Et0/0 NA Sync/En 2 QL-DNU - - Interface: --------------------------------------------- Local Interface: Internal Signal Type: NA Mode: NA(Ql-enabled) SSM Tx: Disable SSM Rx: Disable Priority: 251 QL Receive: QL-SEC QL Receive Configured: - QL Receive Overrided: - QL Transmit: - QL Transmit Configured: - Hold-off: 0 Wait-to-restore: 0 Lock Out: FALSE Signal Fail: FALSE Alarms: FALSE Slot Disabled: FALSE Local Interface: Et0/0 Signal Type: NA Mode: Synchronous(Ql-enabled) ESMC Tx: Enable ESMC Rx: Enable Priority: 2 QL Receive: QL-DNU QL Receive Configured: - QL Receive Overrided: - QL Transmit: - QL Transmit Configured: - Hold-off: 300 Wait-to-restore: 300 Lock Out: FALSE Signal Fail: FALSE Alarms: FALSE Slot Disabled: FALSE Dont Use: FALSE Configured Priority: 2 Force Switch: FALSE Manual Switch: FALSE Manual Switch In progress: FALSE Holdoff_cfg: FALSE Wtr_cfg: FALSE Reason for alarm flag: 0 Msw in progress: FALSE Intf_sig_nv: 0 Hold off Timer: Stopped Wait to restore Timer: Stopped Switchover Timer: Stopped ESMC Tx Timer: Stopped ESMC Rx Timer: Stopped Tsm Delay Timer: Stopped
Example Enabling and Disabling an SNMP Trap in the SyncE Event
The following example shows how to enable and disable an SNMP trap in the SyncE event:
Router > enable Router # configure terminal Router(config)# snmp-server enable traps netsync Router (config)# no snmp-server enable traps netsync Router (config)# end Router# show running-config all| include traps snmp-server enable traps flowmon snmp-server enable traps sonet snmp-server enable traps netsync
Additional References
Related Documents
Related Topic |
Document Title |
---|---|
Cisco IOS commands |
|
Interface and hardware component configuration commands |
Cisco IOS Interface and Hardware Component Command Reference |
Cisco 7600 Synchronous Ethernet |
Standards
Standard |
Title |
---|---|
ITU-T G.8262 |
Timing characteristics of synchronous ethernet equipment slave clock (EEC) |
ITU-T G.8264 |
Timing distribution through Packet Networks |
ITU-T G.781 |
Synchronization layer functions |
MIBs
MIB |
MIBs Link |
---|---|
CISCO-NETSYNC-MIB |
To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
RFC |
Title |
---|---|
None |
-- |
Technical Assistance
Description |
Link |
---|---|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feature Information for Synchronous Ethernet (SyncE) ESMC and SSM
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Feature Name |
Releases |
Feature Information |
---|---|---|
Generating SNMP Trap in SyncE Feature |
15.1(2)S Cisco IOS XE Release 3.8S |
This feature describes how to set SNMP traps in SyncE to notifies the NMS about any unsolicited information. The following commands were introduced or modified by this feature: no snmp-server enable traps netsync, show running-config all| include trap, snmp-server enable traps netsync. |
Synchronous Ethernet (SyncE): ESMC and SSM |
15.0(1)S Cisco IOS XE Release 3.8S |
This feature supports ESMC and the SSM control protocol for SyncE to synchronize clock frequency over an Ethernet port with quality level selection. The following commands were introduced or modified by this feature: esmc mode ql-disabled, esmc process, show esmc, show interfaces accounting. |