Transparent SONET or SDH over Packet (TSoP) Protocol

Table 1. Feature History

Feature Name

Release Information

Description

SFP-TS-OC3STM1-I and SFP-TS-OC12STM4-I Optics Support

 Cisco IOS XE 17.13.1

SFP-TS-OC3STM1-I and SFP-TS-OC12STM4-I Optics support is extended to the following chassis:

  • A900-RSP2A-128

These TSOP smart SFPs can operate in the low latency mode and is used for rail signaling.

Note

 

The support for the ONS-SC-155-TSOP and ONS-SC-622-TSOP are deprecated and are replaced with the new TSoPs SFP-TS-OC3STM1-I and SFP-TS-OC12STM4-I optics, respectively. The software functionalities of the new TSoPs remain the same as the earlier TSoPs.


Note

Transparent SONET or SDH over Packet (TSoP) Protocol is not supported on the Cisco ASR 900 RSP3 module.

The Transparent SONET or SDH over Packet (TSoP) protocol converts SONET or SDH TDM traffic to a packet stream. Operators can now transport SONET or SDH traffic across a packet network by simply adding the TSoP Smart SFP to any router or packet switch. With TSoP the SONET or SDH signal is forwarded transparently, maintaining its embedded payload structure, protection protocols and synchronization. This simplifies the configuration and service turn-up of SONET or SDH connections across the packet network.

Starting with Cisco IOS XE Bengaluru 17.6.1, you can configure the jitter buffer to the lowest value on the Cisco RSP2 module.

Prerequisites for TSoP

  • Single mode optical fiber must be used to connect TSoP Smart SFP with the OC-3 port.

  • The TSoP smart SFP pseudowire endpoints must use the same configuration parameters.

Restrictions for TSoP

  • The TSoP smart SFP payload size is not configurable. The byte size is fixed at 810 bytes.

  • The router cannot be synced with the TSoP Smart SFP clock.

  • Only untagged encapsulation is supported.

  • CFM (connectivity fault management) is not supported.

  • Only QoS Default Experimental marking is supported.

  • TSoP can guarantee a sub 100-millisecond convergence time on SSO.

  • SSO is not supported on TSoP for STM-4 or OC-12 SFP due to hardware restriction.

  • TSoP is not supported on the 10G ports.

  • After setting the low dejitter buffer value and when you change it to a higher value, ensure that you perform shut or no shut of the interface or IM OIR. Then only the new changes are applied on the interface takes place.

Information About TSoP Smart SFP

TSoP Smart SFP is a special type of optical transceiver which provides solution to transparently encapsulate SDH or SONET bit streams into packet format, suitable for pseudowire transport over an ethernet network The TSoP psuedowires is manually configured or setup using PWE3 control protocol [RFC4447].

TSoP provides packetization, de-packetization, and clock recovery that translates the TDM bit stream to fixed size data blocks (810 octets), and vice verse.

TSoP follows the SAToP method described in [RFC4553] for pseudowire transport of E1/DS1, over a packet switched network. With TSoP, the entire OC-3 or STM-1 is encapsulated in a single circuit emulating pseudowire traffic, and is transported it to a single destination across the ethernet network.


Note

The TSoP smart SFP is used on any of the front panel ports of the 8-port Gigabit Ethernet SFP Interface Module (8X1GE).

  • The Smart SFP transceivers is compatible with the Small Form Factor Pluggable 20-pin Multi-Source Agreement (MSA).

  • TSoP Smart SFP (PN: ONS-SC-155-TSOP) transports upto 155 Mbps, on a L1.1 (40km) optical data link.

Guidelines for TSoP Smart SFP

TSoP is compatible with the below SFPs supported on the OC-3 interface module. We recommend you use the specified attenuator:

  • ONS-SI-155-I1—For 15km cable length, use 2 dB attenuator; short distance use 8 dB attenuator to avoid receiver overload.

  • ONS-SI-155-L1—For 40km cable length, no attenuator; short distance use 10 dB attenuator to avoid receiver overload.

  • ONS-SI-155-L2—For 40km cable length, use 2 dB attenuator; short distance use 10 dB attenuator to avoid receiver overload.

    Note

    Multimode SFP is not supported with TSoP.

STM-4 TSoP is compatible with the below SFPs supported on the OC-12 interface module:

  • ONS-SI-622-L2—For 40km cable length, use 2 dB attenuator; short distance use 10 dB attenuator to avoid receiver overload.

  • ONS-SI-622-L1—For 40km cable length, no attenuator; short distance use 10 dB attenuator to avoid receiver overload.

  • ONS-SI-622-I1—For 15km cable length, use 2 dB attenuator; short distance use 8 dB attenuator to avoid receiver overload.


Note

The OC-12 Smart SFP (PN: ONS-SC-622-TSOP) is not supported in Cisco IOS XE Release 3.14S.


Note
Effective Cisco IOS XE Release 3.18, STM-4 TSoP is supported on ASR 900 RSP2 Module .

Configuring the Reference Clock

The reference clock for the TSoP is extracted from the network. You can extract the clock reference from either of the following:

  • Ethernet physical interface

  • Incoming TDM physical interface


Note

If TDM reference clock is configured, and you want to return to the Ethernet reference clock (default), use the ssfpd tsop clock-source ethernet command. Additionally, you can also use the no ssfpd tsop clock-source command to return the Ethernet reference clock (default).

Procedure

  Command or Action Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interface type number

Example:

Device(config)# interface gigabitethernet 0/0/0

Specifies the Gigabit Ethernet interface for configuration and enters interface configuration mode.

Step 4

ssfpd tsop clock-source {ethernet | tdm}

Example:

Device(config)# ssfpd tsop clock-source ethernet
Configures the reference clock on the interface.

  • ethernet —Specifies the ethernet interface as clock source. Default is ethernet.

  • tdm —Specifies the TDM interface as clock source.

Note

 

If Ethernet interface is selected as clock source, the TSoP Smart SFP is synchronized with the Ethernet interface’s clock (where smart SFP is installed), which in turn is synchronized with the network clock (that is already chosen through PTP or SYNC-E).

Step 5

end

Example:

Device(config)# end

Exists configuration and enters privileged EXEC mode

Configuration Examples for TSoP

Sample Configuration

For configuring SONET or SDH controller as in the figure (network A and B), see Configuring Optical Interface Modules.
Figure 1. TSoP in Packet Switched Network


TSoP Smart SFP inserted in the PE’s, CE (SONET or SDH) can be configured as

  • SDH or SONET framing for T1 and E1 mode.

  • Serial interface in SDH or SONET mode. The scale for OC-3 IM is as supported—63 for E1 and 84 for T1 interfaces. The scale supported for OC-12 IM is 252 E1 and 336 T1 interfaces.

  • Multilink interface with minimum of 1 member link and maximum of 16 member link.

  • POS interface in SDH or SONET mode.

  • ATM Layer3 interfaces in SDH or SONET mode.

    Note

    ATM Layer 3 interface is not supported on CE for OC-12 IM.

  • In OC-12 mode, if OC-12 IM is used on CE, only port 0 (ZERO) of the IM is used. Use the card-type command to operate the OC-12 IM.

For configuring the pseudowire using service instances, see Ethernet Virtual Connections Configuration on the Cisco ASR 903 Router.

Note

Only untagged encapsulation is supported.

  • The following example shows a sample configuration on the CE: 

    !
controller SONET 0/2/3			
 framing sdh			
 clock source line			
 aug mapping au-3			
 !			
 !			
 au-3 1			
  overhead j1 length 64			
  mode c-11			
  tug-2 1 t1 1 channel-group 0 timeslots 1			

!

  • The following example shows a sample configuration of the Gigabit Ethernet interface with TSoP smart SFP installed: 

    !
interface GigabitEthernet0/0/0
 no ip address
 negotiation auto
 no keepalive
 service instance 1 ethernet
  encapsulation untagged
  xconnect 2.2.2.2 1 encapsulation mpls

!

Verification Examples

Verifying TSoP Smart SFP

  • Use the show inventory command to display all TSoP Smart SFPs installed on the router. 
    
Router# show inventory
NAME: "subslot 0/0 transceiver 7", DESCR: "TSoP OC-3/STM-1"
PID: ONS-SC-155-TSOP , VID: 01.0, SN: OES18100028
  • Use the show platform software ssfpd db command to display all TSoP Smart SFPs recognized by the router. 
    
Router# show  platform software ssfpd db
=== Smart SFP info ===
dpidx: 14
mac : 00:19:3a:00:2f:18
port: 7
bay: 0
ssfp upgrade data store id: -1
ssfp is device upgrade safe: -1
upgrade percentage complete: 0
ssfp upgrade in progress: 0
  • Use the show platform software ssfpd db command with slot, bay and port to display specific TSoP Smart SFPs recognized by the router. 
    
Router# show platform software ssfpd slot 0 bay 0 port 7 ssfp-d
port 7 ssfp-db
dpidx: 14
mac : 00:19:3a:00:2f:18
port: 7
bay: 0
ssfp upgrade data store id: -1
ssfp device upgrade safe: -1
Upgrade percentage_complete: 0
ssfp upgrade in progress: 0
  • Use the show hw-module subslot command to view information about TSoP Smart SFP. 
    
Router# show hw-module subslot 0/0 transceiver 7 idprom
IDPROM for transceiver GigabitEthernet0/0/7:
Description = SFP or SFP+ optics (type 3)
Transceiver Type: = TSoP OC-3/STM-1 (291)
Product Identifier (PID) = ONS-SC-155-TSOP
Vendor Revision = 01.0
Serial Number (SN) = OES18100028
Vendor Name = CISCO-OES
Vendor OUI (IEEE company ID) = 00.19.3A (6458)
CLEI code = WOTRDBZBAA
Cisco part number = 10-2949-01
Device State = Enabled.
Date code (yy/mm/dd) = 14/03/07
Connector type = LC.
Encoding = 8B10B
NRZ
Nominal bitrate = OC3/STM1 (200 Mbits/s)
The following example shows the configuration of STM-4 TSoP: 
NAME: "subslot 0/5 transceiver 2", DESCR: "TSoP OC-12/STM-4"
PID: ONS-SC-622-TSOP , VID: 01.0, SN: OES17420029

The following example shows the configuration of ASR-920-12CZ-D: 


router#show platform 
Chassis type: ASR-920-12CZ-D

Slot      Type                State                 Insert time (ago) 
--------- ------------------- --------------------- ----------------- 
 0/0      12xGE-2x10GE-FIXED  ok                    7w2d          
R0        ASR-920-12CZ-D      ok, active            7w2d          
F0                            ok, active            7w2d          
P0        ASR920-PSU0         ps, fail              never         
P1        ASR920-PSU1         ok                    never         
P2        ASR920-FAN          ok                    never         

Slot      CPLD Version        Firmware Version                        
--------- ------------------- --------------------------------------- 
R0        20051844            15.6(53r)S                          
F0        20051844            15.6(53r)S

Verifying Clock Source

  • Use the show platform software ssfpd command to display the configured clock source. In the following example, rtpClockSource value for Ethernet clock source is displayed as 0. For TDM clock source the rtpClockSource value is displayed as 1. 
    
Router# show platform software ssfpd slot 0 bay 0 port 7 encap-params
sdId: 14
channel: 0
iwfEncapOutputEnable: 1
ecid: 0
gAisTriggerActive: 0
gAisIncludeLosTrigger: 1
gAisIncludeLofTrigger: 1
insertRtpHeader: 1
rtpClockSource: 0
rtpFrequency: 0
rtpPayloadType: 0
rtpSsrc: 0

Configuring the Low Dejitter Buffer

Table 2. Feature History

Feature Name

Release Information

Description
Support for TSoP SSFP Dejitter Buffer Tuning

Cisco IOS XE Bengaluru 17.6.1

TSoP SSFP Dejitter Buffer Tuning is applicable only for T1 smart SFP.

Dejitter buffer is a buffering mechanism to account for a delay variation in the CEM packet stream.

With the default value, the maximum size of the buffer is utilized. This means that the packets are delayed by default in the middle of the buffering mechanism. Depending on the quality of network, the dejitter buffer can be set to low or high.

If the network quality is high (low amount of packet-delay variation), then the size of the buffer can be set optionally to a low value using the dejitter-buffer low command.

Starting with Cisco IOS XE Bengaluru 17.6.1, you can configure jitter buffer to a lowest value.

To configure the low dejitter buffer, use the following commands:


configure terminal
interface <interface-type>  <slot/subslot/port>
ssfpd tsop dejitter-buffer low
end


Router#configure terminal
Router(config)#interface gigabitethernet 0/0/0
Router(config-if)#ssfpd tsop dejitter-buffer low
Router(config-if)#end

Use the following command to verify the configuration:


Router#show run | sec 0/3/5
interface GigabitEthernet0/3/5
no ip address
shutdown
negotiation auto
no keepalive
ssfpd tsop dejitter-buffer low
service instance 1 ethernet
encapsulation untagged
xconnect 10.10.10.10 111 encapsulation mpls