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Equipment question

We are looking at being offered a CWDM solution with the following specs. What equipment is needed to hook this up? I am not sure if we need a mux (i.e. CWDM-OADM4-1) or if we can use one of the SFP's (CWDM-GBIC-1550=) on a Cisco 3750 switch, or do I need both?

This is being put in to connect our existing site to a new DR site. The carrier has offered us an optical solution with the following specs:

Fiber type: SMF-28

Wavelenght: 1310/1550nm

Hall of Fame Super Silver

Re: Equipment question

If you are the only user of the fiber pair that is being used and there are no active electronics between your sites that are expecting a multiplexed signal, no multiplexing (CWDM) is required. These are sometimes referred to as "IRU" (Indefeasible Right of Use) leases.

Only when you are combining multiple signals on the link (either your own or yours and other customers') is multiplexing required.

Re: Equipment question

Are you being offered a single fiber or a pair (two) fibers?

It looks like they are offering just standard fiber. The length of the fiber link will determine which SFP to select. You don't need to purchase CWDM optics modules: unless you are planning to add more links over the fiber in the future.

New Member

Re: Equipment question

Thanks. Not sure how many pairs are being offered, but I will check. Does it matter though (other than how many SFP's I will need)?

So, all I need is the switch (looking at a 3750) and the one (or two) CWDM SFP?

Re: Equipment question

All you should need are the two switches, each with an SFP installed. If it is a single fiber, Cisco sells an SFP that has built-in WDM filters (1000BASE-BX10-D and 1000BASE-BX10-U SFP for Single-Fiber Bidirectional Applications).

CWDM SFPs may only be required if your carrier is selling you a wavelength on the fiber (they may be sharing the fiber with other customers). Then a CWDM filter will be necessary to couple your signal onto the fiber. The service provider will specify this.

Hall of Fame Super Silver

Re: Equipment question

The CWDM SFP is not necessary unless, as a previous poster said, you are planning to run multiple signals over the fiber (i.e via CWDM or DWDM). Choose the type of SFP based on the end to end loss budget of the fiber link. See, for instance, the following guide:


Re: Equipment question

If carrier is offering you a CWDM solution, is that means he is providing you a wavelength 1550nm to connect your existing site to new DR site.

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