A P P L I C AT I O N N OT E
mTera SONET/SDH Migration
BENEFITS OF INFINERA MTERA
SONET/SDH MIGRATION:
Evolving TDM Networks to OTN/Packet with the
Infinera mTera UTP
■■ Scale STS-1/VC-4 switching to 1.68 Tbps
and 100G+ interfaces
Although spending on SONET/SDH infrastructure has declined over the past decade,
the technology persists in many networks and reliably performs valuable network
functions while delivering high margin revenues. However, network operators with
SONET/SDH infrastructure must contend with high operational costs related to
maintenance, power consumption, and footprint in addition to the increasing challenges
of obtaining replacement parts. The Infinera mTera Universal Transport Platform (UTP),
together with the entire Infinera packet optical portfolio, provides a range of options
for lowering operational costs without losing the high margin revenues generated by
legacy SONET/SDH.
ANALYZING THE DRIVERS FOR SONET/SDH MIGRATION
Following standardization in the late 1980s, SONET/SDH achieved widespread adoption
in the 1990s and became the dominant transport technology for network operators
around the globe. Aided by the evolution to more packet-friendly next-generation
SONET/SDH, network operators continued to invest billions in their SONET/SDH
infrastructure in the 2000s. And despite continued attempts to displace SONET/SDH
over the last fifteen years, the technology remains in the networks of many network
operators as it reliably performs functions such as mobile network synchronization and
delivers highly profitable services to risk-averse end customers.
However, network operators with traditional SONET/SDH networks face a number of
challenges, as shown in Figure 1. In addition to costly maintenance contracts, obtaining
replacement parts can be a challenge as equipment manufacturers discontinue
platforms and/or specific modules due to component obsolescence. Legacy SONET/
SDH equipment also typically requires a larger footprint and higher power consumption
relative to next-generation packet optical platforms. Together, these challenges result in
high operational costs. Furthermore, the majority of SONET/SDH equipment supports a
maximum interface speed of 10 Gbps (OC-192/STM-64), which limits the ability to scale
bandwidth cost effectively.
■■ Protect high margin SONET/SDH
service revenues with Infinera mTera
STS-1/VC-4 and OTN switching, the
Infinera 7090 CEM for TDM Circuit
Emulation, and the Infinera 7100 Pico
for OTN ADM
■■ Deliver end-to-end services with
SONET/SDH to OTN and SONET/SDH
to packet interworking
■■ Avoid high maintenance costs
by replacing legacy SONET/SDH
equipment with future-proof nextgeneration platforms
■■ Reduce power consumption with less
than 3 W per Gbps for STS-1/VC-4
switching, less than 0.7 W per Gbps for
OTN switching, and less than 0.9 W for
packet switching
■■ Minimize the number of 100G+ line
interfaces with efficient STS-1/VC-4
grooming for SONET/SDH
ADM
ET/S
ADM
4
-6
ADM
SON
ADM
DH R
TM
/S
2
-19
ing
Limitations of
Traditional SONET/SDH:
OC
Limited scalability
No 100G interfaces
ADM
ADM
OC-192/STM-64
ADM
D
ET/S
SON
ADM
g
H Rin
ADM
OC
SONET/SDH
Switch (DXC)
ADM
STS-1/VC-4
SONET/SDH Ring
-19
High power consumption
Large footprint
High maintenance costs
Challenges replacing failed parts
2/
ST
M
-6
4
SONET/SDH
Switch (DXC)
STS-1/VC-4
ADM
STS-1/VC-4
ADM
ADM
ADM
STS-1/VC-4
ADM
Manufacturers discontinuing
platforms and/or specific modules
SONET/SDH
Switch (DXC)
Figure 1: Traditional SONET/SDH Network
CONVERGING OTN, PACKET, AND SONET/SDH ON A SINGLE PLATFORM
The mTera UTP provides a number of options for migrating SONET/SDH networks and services to next-generation platforms and technologies.
It provides a future-proof architecture that offers universal switching of packet, OTN, and/or SONET/SDH. The mTera UTP can be deployed as
a standalone OTN switch, a standalone packet switch, or a standalone SONET/SDH switch. Hybrid operation enables OTN switching, different
flavors of packet switching, and/or SONET/SDH switching to function simultaneously in the same shelf and even on the same cards and ports,
thus saving CapEx and footprint. Hybrid operation also enables different switching types to share the same high speed line interfaces, thereby
reducing interface costs and decreasing the number of wavelengths on the optical network.
OTN
MPLS-TP
SONET/
SDH
Carrier
Ethernet
Universal Switching
10G DWDM
100G DWDM
100G/150G/200G
ROADM-on-a-Blade (Optional)
Figure 2: Infinera mTera UTP High Level Overview
2
mTera SONET/SDH Migration
The DWDM layer can be provided by the Infinera 7100 Packet Optical Transport Solutions, Infinera hiT 7300 Multi-Haul Transport Platform, or
third-party DWDM equipment. Alternatively, with its optional ROADM-on-a-blade modules, the mTera UTP can provide a converged packet
optical system with both electrical switching and DWDM.
REPLACING LEGACY SONET/SDH CORE SWITCHES WITH THE 1.68 TBPS MTERA UTP
ADM
ADM
ADM
ing
ADM
ADM
ADM
SONET/SDH Ring
ADM
4
-6
TM
/S
2
-19
OC
DH R
ADM
OC-192/STM-64
ADM
DH
ET/S
SON
ADM
ADM
Ring
ADM
Infinera mTera
OC
-19
2/
ST
M
-6
4
ADM
mTera UTP Benefits:
Up to 1.68 Tbps
STS-1/VC-4 switching
Reduced power consumption
Reduced footprint
Future-proof platform
STS-1/VC-4
ET/S
STS-1/VC-4
SON
ADM
STS-1/VC-4
ADM
STS-1/VC-4
One simple migration option, as shown in Figure 3, is to keep the SONET/SDH ADM rings and replace the core switches/DCSs with the
mTera UTP as a high-capacity STS-1/VC-4 switch. With the SSM-2S modules, the mTera 14-slot shelf can provide up to 1.68 Tbps of STS-1/VC-4
switching in 19RU, and the mTera 8-slot shelf can provide up to 960 Gbps in 10RU (23-inch rack) or 12RU (ETSI or 19-inch rack).
Infinera mTera
Infinera mTera
Figure 3: Replace Core SONET/SDH Switches with the mTera UTP
Additional benefits include reduced power consumption and footprint with STS-1/VC-4 switching at less than 3 W per Gbps and up to 96 Gbps
per rack unit, as shown in Table 1.
Infinera mTera UTP
Legacy SONET/SDH
STS-1/VC-4 Switching
Packet/OTN Switching
Maximum Switch Capacity
320 Gbps ~ 640 Gbps
1.68 Tbps
12 Tbps
Maximum Line Interface
10 Gbps
200 Gbps
200 Gbps
Footprint (Gbps per RU)
15 to 20
Up to 96
Up to 400
Power (W per Gbps)
5 to 10
<3
< 0..7 (OTN), <0.9 (Packet)
Table 1: Legacy SONET/SDH vs. mTera UTP
3
mTera SONET/SDH Migration
LEVERAGING SONET/SDH TO OTN INTERWORKING FOR 100G+ LINE INTERFACES
ET/S
ADM
SONET/SDH Ring
ADM
ADM
mTera UTP Benefits:
100G+ line interfaces
100G+
OTN
ADM
STS-1/VC-4
ing
ADM
ADM
+
0G
10
DH R
Mix SONET/SDH, OTN, and packet
traffic on the same 100G+ interfaces
OTN
ADM
SON
ADM
STS-1/VC-4
ADM
OTN
ADM
STS-1/VC-4
As shown in Figure 4, leveraging mTera UTP SONET/SDH to OTN interworking, the STS-1/VC-4 traffic can be mapped to OTN and transported
over high speed 100G and flexi-rate (100G/150G/200G) line interfaces. Optionally, these interfaces can be shared with other OTN switched
and packet switched traffic to maximize their utilization.
Reduced power consumption
E
SON
ADM
ADM
Infinera mTera
10
0G
+
ADM
ADM
Reduced footprint
OTN
ing
STS-1/VC-4
ADM
HR
T/SD
Up to 1.68 Tbps
STS-1/VC-4 switching
Infinera mTera
Future-proof platform
Infinera mTera
Figure 4: Transport SONET/SDH over 100G+ Line Interfaces
SCALING ETHERNET OVER SONET/SDH WITH A PACKET SWITCHED CORE
ADM
ET/S
ing
ADM
ADM
ADM
SONET/SDH Ring
ADM
ADM
mTera UTP Benefits:
100G+
PACKET
ADM
+
0G
0
1
DH R
STS-1/VC-4
SON
ADM
Extend mTera packet switching
to Ethernet interfaces on
SONET/SDH ADMs
PACKET
ADM
STS-1/VC-4
ADM
PACKET
Ethernet over SONET/SDH
STS-1/VC-4
Another option is to leverage mTera UTP SONET/SDH to packet interworking, taking Ethernet over SONET/SDH traffic from the ADM rings,
terminating the SONET/SDH, and then mapping the Ethernet traffic into a packet switching instance on the mTera UTP. In this way, the full
packet feature set of the mTera can be extended to Ethernet interfaces on the ADMs, and end-to-end Ethernet services can be delivered
over multiple transport switching domains. This application can be supported in parallel to the previously described applications with packet,
SONET/SDH, and OTN switching able to share the same physical mTera hardware and interfaces.
ADM
ADM
Infinera mTera
10
0G
+
PACKET
ADM
DH
ET/S
SON
ADM
Ring
STS-1/VC-4
ADM
Infinera mTera
Infinera mTera
Figure 5: Ethernet over SONET/SDH to Packet Interworking
4
mTera SONET/SDH Migration
End-to-end MEF Ethernet services
over multiple transport domains
Scalable packet core with 100G+
interfaces
Statistical gains and granularity of
packet switching
MIGRATING SONET/SDH RINGS TO UNIVERSAL TRANSPORT WITH THE MTERA UTP
Par
ADM
ADM
14-Slot mTera
10
0G
+
8-Slot mTera
OTN
OTN
h
es
tial M
mTera UTP Benefits:
Option of compact 8-slot mTera
OTN
Packet
100G+
Packet
mTera Ring
OTN
ing
STS-1/VC-4
ADM
ADM
+
0G
0
1
DH R
14-Slot mTera
Migrate from ring to mesh or
partial mesh topologies
Scale rings to 100G+
Mix SONET/SDH, packet, OTN, and
DWDM on the same platform
Introduce incrementally or
replace entire rings
Packet
ET/S
STS-1/VC-4
ADM
SON
ADM
Packet
ADM
STS-1/VC-4
ADM
STS-1/VC-4
In addition to deploying the high-capacity 14-slot mTera as a replacement for core SONET/SDH switches and DCSs, network operators have
the option to extend the benefits of universal transport to the SONET/SDH rings by replacing either entire rings or individual nodes with either
the higher capacity 14-slot mTera or the more compact 8-slot mTera. The 8-slot mTera provides 960 Gbps of STS-1/VC-4 switching and up to 4
Tbps of OTN/packet switching and can be mounted horizontally consuming 10RU in a 23-inch rack or vertically consuming 12RU in a 19-inch
or ETSI rack. In addition, the mTera SONET/SDH protection and restoration schemes can be combined with OTN protection and restoration to
provide end-to-end resiliency from the SONET/SDH rings over the OTN core.
14-Slot mTera
Figure 6: Migrate SONET/SDH Rings with the mTera UTP
COMPLEMENTING THE MTERA WITH THE INFINERA 7090 CEM FOR T1/E1 CES
The mTera UTP supports STM-1/OC-3, STM-4/OC-12, STM-16/OC-48, and STM-64/OC-192 SONET/SDH interfaces. Where there is a need to
support lower speed TDM interfaces such as T1/E1, the Infinera 7090 Packet Transport Solutions CEM platforms can complement mTera UTP
rings with the ability to provide TDM Circuit Emulation Services (CES) over MPLS-TP with support for T1/E1, DS3, OC-3/STM-1, OC-12/STM-4,
and OC-48/STM-16 interfaces, as shown in Figure 7.
T1/E1/CES
mTera 8
T1/E1/CES
10
0G
+
OTN
14-Slot mTera
14-Slot mTera
Figure 7: E1/T1 CES with the Infinera 7090 CEM
5
mTera SONET/SDH Migration
OTN
OTN
14-Slot mTera
OTN
ing
aR
mTer
100G+
Packet
mTera Ring
Packet
+
0G
10
ADM
STS-1/VC-4
ing
STS-1/VC-4
T1/E1/CES
ADM
mTe
ra R
Packet
ADM
Packet
ADM
STS-1/VC-4
ADM
STS-1/VC-4
T1/E1/CES
Infinera 7090 CEM Benefits:
TDM CES:
T1/E1
DS3
OC-3/STM-1
OC12/STM-4
OC-48/STM-16
Synchronization:
Synchronous Ethernet
1588v2
Platforms: 8 Gbps to 960 Gbps
REPLACING SONET/SDH RINGS WITH OTN ADMs AND STS-1/VC-4 SWITCHING IN THE CORE
+
0G
10
Infinera mTera
10
0G
+
OC-3/STM-1
OTN
Increased ring capacity (100G)
Reduced maintenance costs
Future-proof platforms
STS-1/VC-4 grooming at core
maximizes the utilization of 100G+
line interfaces
Infinera mTera
OTN
OTN
100G+
OTN
1
mTera + Pico OTN ADM:
Cost-effective OTN ADMs
Low power and small footprint
STS-1/VC-4
ing
TN R
0G O
STS-1/VC-4
100G OTN Ring
OTN
ing
OTN
OTN
R
STS-1/VC-4
ADM
10G
OTN
OTN
OC-3/STM-1
STS-1/VC-4
OTN ADMs provide another option for migrating SONET/SDH rings. The 2RU Infinera 7100 Pico Packet Optical Transport Platform can provide
a compact 100G ADM with a pair of HGTM-MS2 100G muxponder/ADM modules. Alternatively, a 10G ADM option is available with the OMM-X
module, which provides two 10G/OTU2 line interfaces and eight low speed SFP client ports. SONET/SDH traffic can be mapped to ODU0s,
ODU1s, or ODU2s and then transported over the 10G or 100G OTN ring to the mTera UTP.
Infinera mTera
Figure 8: OTN to the Edge with STS-1/VC-4 Grooming in the Core
At the mTera UTP, this traffic can either be switched natively as with OTN or it can be sent to an SSM-2S module for STS-1/VC-4 grooming
before being mapped back to OTN. This STS-1/VC-4 grooming can result in much more efficient utilization of high speed line interfaces, for
example enabling an OTU4 to carry 640 STM-1s/OC-3s, rather than 80 OC-3s/STM-1s when OC-3s/STM-1s are carried in ODU0s, as shown in
Figure 9.
Native OTN Switching
OTN Switching with STS-1/VC-4 Grooming
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU0
ODU4
80xOC-3/STM-1 = 12.5% Utilization
ODU2
ODU2
ODU2
ODU2
ODU2
mTera SONET/SDH Migration
ODU2
ODU2
ODU2
ODU4
640xOC-3/STM-1 = 100% Utilization
Figure 9: Native OTN Switching vs. OTN Switching with STS-1/VC-4 Grooming
6
ODU2
ODU2
REPLACING SONET/SDH RINGS WITH PACKET/TDM CES RINGS
An additional option for the SONET/SDH rings is to migrate them to packet switching based on MPLS-TP, including VPLS/H-VPLS, with TDM
CES for the TDM interfaces, leveraging the 7090 CEM Series. Benefiting from the granularity and statistical gains of packet, these rings can
be used to deliver both Ethernet and TDM services through the mTera UTP as it provides a scalable core packet switch with the additional
ability to perform SONET/SDH and OTN switching.
TDM CES
Infinera
7090
CEM
g
10G
g
t Rin
e
Pack
OTN
100G+
Infinera mTera
10
0G
+
TDM CES
OTN
100G Packet Ring
Infinera mTera
MPLS-TP with hard QoS
Statistical gain and granularity
of packet
Low power and small footprint
Reduced maintenance costs
Future-proof Platforms: 8 Gbps
to 960 Gbps
STS1/VC-4
Packet
TDM CES
Ethernet Clients: FE/FX, GE,
10GE, 100GE
OTN
+
0G
0
1
t Rin
Packet
Pack
e
OTN
10G
STS1/VC-4
ADM
TDM CES: T1/E1, DS3, OC-3/STM-1,
OC-12/STM-4, OC-48/STM-16
STS1/VC-4
ADM
Packet
ADM
Infinera 7090 CEM Rings:
10GE and 100GE rings
STS1/VC-4
TDM CES
Packet
Ethernet
Infinera mTera
Figure 10: Packet/CES Rings with the Infinera 7090 CEM
DELIVERING END-TO-END SERVICES WITH SONET/SDH-PACKET AND SONET/SDH-OTN
INTERWORKING
Leveraging its universal switching and interworking capabilities, the mTera UTP can provide a gateway between the SONET/SDH domain
and other transport domains based on OTN, MPLS-TP, and Carrier Ethernet technologies. The mTera UTP can enable end-to-end TDM
and Ethernet services that span the SONET/SDH domain and the OTN domain. Universal switching can also enable end-to-end Ethernet
services that span the SONET/SDH domain and packet domains including MPLS-TP/H-VPLS, Carrier Ethernet VLAN cross-connect, and
Carrier Ethernet bridging.
mTera UTP
Packet
SONET/SDH
domain
STS-1/VC-4
OTN
OTN
Switched
domain
Figure 11: End-to-end Services Gateway
7
mTera SONET/SDH Migration
MPLS-TP
domain
VLAN XC
domain
Bridging
domain
FEATURING THE MTERA SSM-2S SONET/SDH SWITCHING MODULE
The mTera SSM-2S module provides six 10G SFP+ ports for OC-192/STM-64 and twenty-four SFP ports for OC-3/OC-12/OC-48/STM-1/STM-4/
STM-16. 120 Gbps of native STS-1/VC-4 traffic per SSM-2S module can be switched between ports on the same SSM-2S module and between
ports on different SSM-2S modules via the backplane and mTera universal fabrics. The SSM-2S therefore is designed to enable up to 1.68 Tbps
of STS-1/VC-4 switching in the 14-slot mTera and 960 Gbps in the 8-slot mTera.
120G STS-1/VC-4
SSM-2S
24xSFP (OC-3/STM-1, OC-12/STM-4, OC-48/STM-16)
6x10G SFP+ (OC-192/STM-64)
Native
STS-1/VC-4
OTN
Interworking
(60 Gbps)
Packet
Interworking
(30 Gbps)
OTN
Packet
BACKPLANE UNIVERSAL FABRICS
Figure 12: mTera SSM-2S SONET/SDH Switching Module
The SSM-2S module is designed to also support:
■■
SONET/SDH to OTN interworking: 60 Gbps of STS-1/VC-4 traffic from the same module or other SSM-2S modules mapped to OTN
and switched to the mTera OSM OTN/packet modules
■■
SONET/SDH to packet interworking: Terminate up to 30 Gbps of Ethernet over SONET/SDH traffic from the SONET/SDH ports and
switch the Ethernet traffic into the packet switching on the mTera OSM OTN/packet modules
■■
Synchronization: Stratum 3 clocks in the mTera timing and processor modules with timing references coming from either the
interfaces on the switching modules or external timing interfaces (T1/E1/2MHz) in the shelf common equipment
■■
SONET/SDH protection: UPSR, SNC, 1+1 APS, and 1+1 MSP
■■
ASON/GMPLS protection and restoration: STS-1/VC-4
SONET/SDH resiliency schemes can also be combined with the mTera packet and OTN resiliency schemes including ODUk-level ASON/
GMPLS protection and restoration.
MIGRATING WITH INFINERA PROFESSIONAL SERVICES
Infinera offers comprehensive professional services to assist with the migration of SONET/SDH networks. These professional services
follow a four-phase process, as shown in Figure 13. The first phase provides a network audit that includes: identifying the targeted network
elements, conducting a field audit, and gathering each network element configuration and the physical and logical circuit assignments.
This process enables Infinera Professional Services to determine the high level project scope.
8
mTera SONET/SDH Migration
Project/Program
Management
Phase I: Network Audit & Records Reconciliation
Phase II: Network Analysis, Migration Design & Equipment Build-out Specifications
Phase III: Network Build-out & Network Circuit Test
Phase IV: Network Migration Execution
Figure 13: Infinera Professional Services Process for SONET/SDH Migration
The second phase in the migration of SONET/SDH networks includes network analysis, a migration plan and procedures, and equipment
selection and deployment. The third phase consists of provisioning the new network elements, installing new facility wiring/optics, and testing
the end-to-end circuits. The fourth and final phase includes executing the facility/service migrations, verifying the alarms, and updating the new
circuit designs in the OSS and other support systems.
SUMMARY
Though SONET/SDH networks continue to deliver high margin services to risk-averse customers and perform useful network functions
such as mobile network synchronization, they suffer from high operational costs and the threat of component obsolescence. The mTera
UTP, together with the 7090 CEM and 7100 Pico, provides a range of options for migrating SONET/SDH networks to next-generation OTN/
packet technologies and future-proof platforms while lowering operational costs and protecting SONET/SDH service revenues. These
Infinera solutions can also deliver a wide range of additional services based on their OTN switching, packet switching, and DWDM/ROADM
capabilities.
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Statements herein may contain projections regarding future products, features, or technology and resulting commercial or technical
benefits, which are subject to risk and may or may not occur. This publication is subject to change without notice and does not
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specifications or warranties. 0012-AN-RevA-0519