Source: Infinera
Infinera has unveiled its latest metro products that support up to 200-gigabit wavelengths using CFP2-DCO pluggable modules.
The XTM II platform family is designed to support growing metro traffic, low-latency services and the trend to move sophisticated equipment towards the network edge. Placing computing, storage and even switching near the network edge contrasts with the classical approach of backhauling traffic, sometimes deep within the network.
“If you backhaul everything, you really do not know if it belongs in that part of the network,” says Geoff Bennett, director, solutions and technology at Infinera. Backhauling inherently magnifies traffic whereas operators want greater efficiencies in dealing with bandwidth growth, he says: “This is where the more cloud-like architectures towards the network edge come in.”
But locating equipment at the network edge means it must fit within existing premises or in installed prefabricated huts where space and the power supplied are constrained.
“If you are asking service providers to put more complex equipment there, then you need low power utilisation,” says Bennett. “This has been a key piece of feedback from customers we have been asking as to how they want our existing products to evolve in the metro-access.”
Having a distributed switch fabric is a long-term advantage for Infinera
Infinera says its latest XTM II products are eight times denser in terms of tranmission capacity while setting a new power-consumption low of 20W-27W per 100 gigabits depending on the operating temperature (25oC to 55oC). Infinera claims its nearest metro equipment competitor achieves 47W per 100 gigabits.
Sterling Perrin, principal analyst, optical networking and transport at Heavy Reading, says Infinera has achieved the power-efficient design by using a distributed switch architecture rather that a central switch fabric and adopting the CFP2-DCO pluggable module with its low-power coherent DSP.
“If you have a centralised fabric and you put it into an edge application then for some cases it will be a perfect fit but for many applications, it will be overkill in terms of capacity and hence power,” says Perrin. “Infinera is able to do it in a modular fashion in terms of just how much capacity and power is put in an application.”
Having a distributed switch fabric is a long-term advantage for Infinera for these applications, says Perrin, whereas competitor vendors will also benefit from the CFP2-DCO for their next designs.
And even if a competitor uses a distributed design, they will not leapfrog Infinera, says Perrin, although he expects competitors’ designs to come down considerably in power with the adoption of the CFP2-DCO.
Infinera has chosen not to use its photonic integrated circuit (PIC) technology for its latest metro platform given the large installed base of XTM chassis that already use pluggable modules. “It would make sense that customers would give feedback that they want a product that has industry-leading performance but which is also backwards compatible,” says Bennett.
Infinera has said it will evaluate whether its PIC technology will be applied to each new generation of the product line. “So when you get to the XTM III they will have another round looking at it,” says Perrin. “If I were placing bets on the XTM III, I would say they are going to continue down this route [of using pluggables].”
Perrin expects line-side pluggable technology to continue to progress with companies such as Acacia Communications and the collaboration between Ciena with its WaveLogic DSP technology and several optical module makers.
“At what point is the PIC going to be better than what is available with the pluggables?” says Perrin. “For this application, I don’t see it.”
XTM II family
Infinera has already been shipping upgraded XTM chassis for the last 18 months in advance of the launch of its latest metro cards. The upgraded chassis - the one rack unit (1RU) TM-102/II, the 3RU TM-301/II and the 11RU TM-3000/II - all feature enhanced power management and cooling.
What Infinera is unveiling now are three cards that enhance the capacity and features of the enhanced chassis. The new cards will work with the older generation XTM chassis (without the ‘II’ suffix) as long as a vacant card slot is available and the chassis’ total power supply is not exceeded. This is important given over 30,000 XTM chassis have been deployed.
The Infinera cards announced are the 400-flexponder, a 200-gigabit muxponder, and the EMXP440 packet-optical transport switch. The distributed switch architecture is implemented using the EMXP440 card.
Operators will also be offered Infinera’s Instant Bandwidth feature as part of the XTM II whereby they can pay for the line side capacity they use: either 100-gigabit or 200-gigabit wavelengths using the CFP2-DCO. The Instant Bandwidth offered is not the superchannel format available for Infinera’s other platforms that use its PIC but it does offer operators the option of deploying a higher-speed wavelength when needed and paying later.
400G flexponder
The flexponder can operate as a transponder and as a muxponder. For a transponder, the client signal and line-side data rate operate at the same data rate. In contrast, a muxponder aggregates lower data-rate client signals for transport on a single wavelength.
Infinera’s 400-gigabit flexponder card uses four 100 Gigabit Ethernet QSFP28 client interfaces and two 200-gigabit CFP2-DCO pluggable line-side modules. Each CFP2-DCO can transport data at 100 gigabits using polarisation-multiplexing, quadrature phase-shift keying (PM-QPSK) modulation or at 200 gigabits using 16-ary quadrature amplitude modulation (PM-16QAM).
The 400-gigabit card can thus operate as a transponder when the CFP2-DCO transports at 100 gigabits and as a muxponder when it carries two 100-gigabit signals over a 200-gigabit lambda. Given the card has two CFP2 line-side modules, it can even operate as a transponder and muxponder simultaneously.
The flexponder card also supports OTN block encryption using the AES-256 symmetric key protocol.
The flexponder is an upgrade on Infinera’s existing 100-gigabit muxponder card. The eightfold increase in capacity is achieved by using two 200-gigabit ports instead of a single 100-gigabit module and halving the width of the line card.
Using the flexponder card, the TM-102/II chassis has a transport capacity of 400 gigabits, up to 1.6 terabits with the TM-301/II and a total of 4 terabits using the TM-3000/II platform.
We can dial back the FEC if you need low latency and don't need the reach
200G muxponder
The double-width 200G card includes all the electronics needed for multi-service multiplexing. The line-side optics is a single CFP2-DCO module whereas the client side can accommodate two QSFP28s and 12 SFP+ 10-gigabit modules. The card can multiplex a mix of services including 10GbE, 40GbE, and 100GbE; 8-, 16- and 32-gigabit Fibre Channel; OTN and legacy SONET/SDH traffic.
Other features include support for OTN block encryption using the AES-256 symmetric key protocol.
The card’s forward error correction performance can also be traded to reduce the traffic latency. “We can dial back the FEC if you need low latency and don't need the reach,” says Bennett.
OTN add-drop multiplexing can also be implemented by pairing two of the multiplexer cards.
EMXP440 switch and flexible open line system
The EMXP440 packet-optical transport switch card supports layer-two functionality such as Carrier Ethernet 2.0 and MPLS-TP. “Mobile backhaul and residential broadband, these are the cards the operators tend to use,” says Bennett.
The two-slot EMXP440 card has two CFP2-DCOs and 12 SFP+ client-side interfaces. The reason why the line side and client side interface capacity differ (400 gigabits versus 120 gigabits) is that the card can be used to build simple packet rings (see diagram, top).
The line-side interfaces can be used for ‘East’ and ‘West' traffic while the SFP+ modules can be used to add and drop signals. The EMXP440 card also has an MPO port such that up to 12 SFP+ further ports can be added using Infinera’s PTIO-10G card, part of its PT Fabric products.
A flexible grid open line system is also available for the XTM II. The XTM II’s 100-gigabit and 200-gigabit wavelengths fit within a 50GHz-wide fixed grid channel but Infinera is already anticipating future higher baud rates that will require channels wider than 50GHz. A flexible grid also improves the use of the fibre’s overall capacity. In turn, RAMAN amplification will also be needed to extend the reach using future higher order modulation schemes such as 32- and 64-QAM.
Infinera says the 400-gigabit flexponder card will be available in the next quarter while the 200-gigabit muxponder and the EMXP440 cards will ship in the final quarter of 2017.