Data center bandwidth demands continue to grow, requiring higher capacity and throughput. The 100G/120G Ethernet is no longer new in data center optic market, but it’s still a complex act to efficiently and effectively upgrade existing 10G/40G architectures to these higher data rates, especially in a space-constrained application. In order to explore the approaches of smooth migration to high density 100G/120G network, this post will take multimode 100G/120G CXP module as example, and illustrate some simplified scenarios when upgrading to these higher data rates.
Overview on 120G CXP Module
High density 100G CXP is very popular in the implementations up to 100Gbps for saving-space. This deployment can then leverage the 10G-per-lane channels to distribute the 10G data anywhere in the data center. 100G CXP module is designed to connect with an MTP/MPO-24 connector, which can be divided to 10x10G or 12x10G transceiver pairs. For 120G CXP, it is also possible to separate the signals into three QSFP+ transceivers, and then to three groups of 4x10G transceivers by using an 8 fibers MTP/MPO to LC breakout module or cable.
Direct Connectivity for Two CXPs
For two 100GBASE-SR10 modules, direct link can be easily made via 100G MPO cable. For connecting two 120G CXPs, a cost-effective 24 fibers MPO trunk can also work well. Here uses an 24 fibers MPO (female) to MPO (female) OM4 polarity B trunk cable.
Figure 1: direct link for two 100G CXP modules
Connectivity Methods for 120G CXP and SFP+/QSFP+
In this part, the scenarios applied for 100G to 10G connection, and 120G to 40G or 10G connection will be explained.
100G to 10G
Figure 2 shows a direct link for one 100G CFP module and ten 10G SFP+ modules. By using the 24 fibers MPO to LC duplex harness cable, the whole 100G from the CFP transceiver is connected to ten SFP+ transceivers (two LC duplex legs are not used in this link). The fanout legs are available to be the same length or staggered type, so as to meet different applications.
Figure 2: direct link for a 100G CFP to 10x10G SFP+s
In figure 3, the interconnect for CFP and SFP+ transceivers is more flexible than the direct link. Here the 160 fibers MTP/MPO (male) breakout patch panel allows connectivity to any duplex path reachable by the patch panel. This method offers ultimate flexibility in allowing connectivity to any row, rack or shelf. Moreover, this breakout module can support up to eight groups of this 100G to 10x10G transmission. In such a high density link, it is suggested to use HD patch cables or LC uniboot patch cables to enable quicker and better cable management.
Figure 3: interconnect solution for 100G CFP to 10x10G SFP+s
120G to 10G and 40G
When directly connecting one 120G CXP to twelve 10G SFP+ transceivers, a 24 fibers MTP-24 to 12 LC harness cables can do the job well. Here we use a customized high density bend insensitive female MTP-24 to 12 LC duplex OM4 breakout cable.
Figure 4: direct link for 120G to 12x10G transceivers
An option for breaking out a 120G CXP to three 40G QSFP+s is to use the 1×3 MTP/MPO conversion harness cable. Figure 5 illustrates implementation of a 1×24 strand MTP to 3×8 strand MTP conversion harness cable. Like the 12x10G segregation mentioned above, once split, the 3×8-fiber QSFP+ channels can be distributed through patch panels and 12-fiber based trunking to any area of the data center.
Figure 5: hybrid link for 120G CXP to 40G QSFP+s and 10G SFP+s
This article has illustrated some simplified implementation examples of 100G CXP modules. 24 fibers MTP/MPO trunk cable are suited for connecting two CXP modules. Breakout cables can achieve quick connection for CXP and QSFP+ or SFP+ optics, but when flexible patching is needed in the link, it would be better to adopt breakout patch panel.