There two ways to deploy 40GbE multimode fiber (MMF) infrastructure. One is using the parallel transceivers with 12-fiber MTP cables. And the other one is to use the duplex transceivers with LC duplex cables (view transceiver options for 40GbE over duplex LC MMF cable). The former solution requires to add additional fiber to increase the number of 40GbE links. Thus, more fiber cost is taken in this solution. Conversely, the duplex transceiver solution allows for zero-cost fiber migration by reusing the current 10GbE fiber infrastructure for 40GbE connectivity. In this post, the typical cost difference for fiber infrastructure for parallel transceivers and duplex transceiver is introduced.
In this scheme, a pairs of 40GbE parallel transceivers called 40GBASE-SR4 QSFP+ are used with the MTP patch cables and trunks. In addition, two MTP-MTP conversion modules are required. As shown in the picture below, there are two patch cables, two MTP-MTP conversion modules, and a 24-fiber trunk per link. Since the QSFP-40G-SR4 just uses 8 fibers in the trunk per link, total two MTP-MTP conversion modules can be used for 3 links.
The detailed cost for per 40GbE link with parallel transceivers are shown in the following table:
| Item | Unit Price | Extended Price Per 40GbE Link |
| MTP patch cables (5 m, OM3) | US$48.00 | US$96.00 |
| MTP-MTP conversion modules (OM3) | US$400.00 | US$267.00 |
| 24-fiber MTP trunk (90 m, OM3) | US$367.00 | US$123.00 |
| Total | US$486.00 | |
In the scheme using duplex transceivers, such as Juniper JNP-QSFP-40G-LX4 or Arista 40G QSFP-UNIV, two LC patch cables, two MTP-LC cassettes and a 24-fiber MTP trunks are used. As shown in the picture below, by deploying the duplex 40GbE transceivers, users can increase the number of 40G links by 4X without making any changes to their fiber infrastructure. In other word, the total two MTP-LC cassettes can be used for 12 links.
The detailed cost for per 40GbE link with duplex transceivers are shown in the following table:
| Item | Unit Price | Extended Price Per 40GbE Link |
| Duplex LC patch cables (5 m, OM3) | US$4.00 | US$8.00 |
| MTP-LC cassettes (OM3) | US$120.00 | US$20.00 |
| 24-fiber MTP trunk (90 m, OM3) | US$367.00 | US$30.00 |
| Total | US$58.00 | |
The prices of product above are estimated according to FS.COM list prices (for reference only). Assume shipping costs are the same, as you see, a saving of over 90% on the cabling equipment alone is realized from the duplex transceivers. The project management costs to upgrade existing duplex systems are entirely avoided resulting in even more significant savings. In addition, the duplex transceivers mentioned above can also support running over single-mode fiber which is a cost-effective solution for migrating from multimode to single-mode fiber.
However, it is noted that the duplex 40GbE multimode transceiver is more expensive than the parallel one. For example, the 40GBASE-SR4 costs just 65 dollors while the LX4 costs about 400 dollors at FS.COM. Thus, the best option is just to choose the one you need, based on your network plan and future-proof upgrade.
| Buyer Guides: At FS.COM, you can buy the above products at very affordable prices. In addition, you can buy both parallel and duplex 40GbE transceivers for many major brands compatible. For more information, please contact sales@fs.com. |
Related Article: 40G Transceiver Module: QSFP+ Module And CFP Module
