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MX10004 Transceiver and Cable Specifications

Your transceiver and network cable plan for the MX10004 router must take into consideration the fiber-optic cables you can use, including connector details and pinouts. For optimal router function, your site must meet cable power requirements and mitigate cable signal loss, attenuation, and dispersion.

To ensure success, review fiber-optic cable characteristics. Plan the power budget and power margin for fiber-optic cables connected to your device by using the information in the following topics.

MX10004 Optical Transceiver and Cable Support

You can find information about the pluggable transceivers supported on your Juniper Networks device by using the Hardware Compatibility Tool. In addition to transceiver and connector type, compatibility tool documents the optical and cable characteristics—where applicable—for each transceiver. The Hardware Compatibility Tool enables you to search by product, displaying all the transceivers supported on that device (or category) by interface speed or type. The list of supported transceivers for the MX10004 is located at Hardware Compatibility Tool.

CAUTION:

The Juniper Networks Technical Assistance Center (JTAC) provides complete support for Juniper-supplied optical modules and cables. However, JTAC does not provide support for third-party optical modules and cables that are not qualified or supplied by Juniper Networks. If you face a problem running a Juniper device that uses third-party optical modules or cables, JTAC may help you diagnose host-related issues if the observed issue is not, in the opinion of JTAC, related to the use of the third-party optical modules or cables. Your JTAC engineer will likely request that you check the third-party optical module or cable and, if required, replace it with an equivalent Juniper-qualified component.

Use of third-party optical modules with high-power consumption (for example, coherent ZR or ZR+) can potentially cause thermal damage to or reduce the lifespan of the host equipment. Any damage to the host equipment due to the use of third-party optical modules or cables is the users’ responsibility. Juniper Networks will accept no liability for any damage caused due to such use.

MX10004 Cable Specifications for Console and Management Connections

Table 1 lists the specifications for the cables that connect the MX10004 router to a management device.

Note:

You can configure the MX10004 with small form-factor pluggable (SFP) management ports that support 1000BASE-SX transceivers.
Table 1: Cable Specifications for Console and Management Connections for the MX10004 Routers

Port on MX10004 Router

Cable Specification

Maximum Length

Device Receptacle

Console port

RS-232 (EIA-232) serial cable

2.13 meters

RJ-45

Management port

Category 5 cable or equivalent suitable for 1000BASE-T operation

100 meters

RJ-45
Note:

We no longer include the RJ-45 console cable with the DB-9 adapter as part of the device package. If the console cable and adapter are not included in your device package, or if you need a different type of adapter, you can order the following separately:

  • RJ-45 to DB-9 adapter (JNP-CBL-RJ45-DB9)

  • RJ-45 to USB-A adapter (JNP-CBL-RJ45-USBA)

  • RJ-45 to USB-C adapter (JNP-CBL-RJ45-USBC)

If you want to use RJ-45 to USB-A or RJ-45 to USB-C adapter you must have X64 (64-Bit) Virtual COM port (VCP) driver installed on your PC. See, https://ftdichip.com/drivers/vcp-drivers/ to download the driver.

MX10004 Fiber-Optic Cable Signal Loss, Attenuation, and Dispersion

To determine the power budget and power margin needed for fiber-optic connections, you need to understand how signal loss, attenuation, and dispersion affect transmission. The MX10004 router uses various types of network cables, including multimode and single-mode fiber-optic cables.

Signal Loss in Multimode and Single-Mode Fiber-Optic Cables

Multimode fiber is large enough in diameter to allow rays of light to reflect internally (bounce off the walls of the fiber). Interfaces with multimode optics typically use LEDs as light sources. However, LEDs are not coherent light sources.

LEDs spray varying wavelengths of light into the multimode fiber, which reflects the light at different angles. Light rays travel in jagged lines through a multimode fiber, causing signal dispersion. Fiber cladding consists of layers of lower-refractive index material in close contact with a core material of higher-refractive index. When light traveling in the fiber core radiates into the fiber cladding, higher-order mode loss occurs. Together, these factors reduce the transmission distance of multimode fiber compared with that of single-mode fiber.

Single-mode fiber is so small in diameter that rays of light reflect internally through one layer only. Interfaces with single-mode optics use lasers as light sources. Lasers generate a single wavelength of light, which travels in a straight line through the single-mode fiber. Compared with multimode fiber, single-mode fiber has a higher bandwidth and can carry signals for longer distances. It is consequently more expensive.

For information about the maximum transmission distance and supported wavelength range for the types of single-mode and multimode fiber-optic cables that are connected to the MX Series, see the Juniper Networks Hardware Compatibility Tool. Exceeding the maximum transmission distances can result in significant signal loss, which causes unreliable transmission.

Attenuation and Dispersion in Fiber-Optic Cables

An optical data link functions correctly if the modulated light reaching the receiver has enough power to be demodulated correctly. Attenuation is the reduction in strength of the light signal during transmission. Passive media components such as cables, cable splices, and connectors cause attenuation. Although attenuation is significantly lower for optical fiber than for other media, it still occurs in both multimode and single-mode transmissions. An efficient optical data link must transmit enough light to overcome attenuation.

Dispersion is the spreading of the signal over time. The following two types of dispersion can affect signal transmission through an optical data link:

  • Chromatic dispersion, which is caused by the different speeds of light rays.

  • Modal dispersion, which is caused by the different propagation modes in the fiber.

For multimode transmission, modal dispersion usually limits the maximum bit rate and link length. (Chromatic dispersion or attentuation does not usually limit the maximum bit rate or link length.) For single-mode transmission, modal dispersion is not a factor. However, at higher bit rates and over longer distances, chromatic dispersion limits the maximum link length.

An efficient optical data link must have enough light to exceed the minimum power that the receiver requires to operate within its specifications. In addition, the total dispersion must be within the limits specified for the type of link in the Telcordia Technologies document GR-253-CORE (Section 4.3) and International Telecommunications Union (ITU) document G.957.

When chromatic dispersion is at the maximum allowed, its effect can be considered as a power penalty in the power budget. The optical power budget must allow for the sum of component attenuation, power penalties (including those from dispersion), and a safety margin for unexpected losses.

Calculate the Fiber-Optic Cable Power Budget for an MX10004 Router

Calculate the link's power budget when planning fiber-optic cable layout and distances to ensure that fiber-optic connections have sufficient power for correct operation. The power budget is the maximum amount of power the link can transmit. When you calculate the power budget, you use a worst-case analysis to provide a margin of error, even though the parts of a configured system don’t operate at the worst-case levels. We cannot use the phrase "all parts . . . don't operate." You can write "none of the parts operate," however.

To calculate the worst-case estimate for the fiber-optic cable power budget (PB) for the link:

  1. Determine values for the link's minimum transmitter power (PT) and minimum receiver sensitivity (PR). For example, in the following example, we measure (PT) and (PR) in decibels per milliwatt (dBm):

    PT = –15 dBm

    PR = –28 dBm

    Note:

    See the specifications for your transmitter and receiver to find the minimum transmitter power and minimum receiver sensitivity.
  2. Calculate the power budget (PB) by subtracting (PR) from (PT):

    –15 dBm – (–28 dBm) = 13 dBm

Calculate the Fiber-Optic Cable Power Margin for an MX10004 Router

Before you begin to calculate the power margin, calculate the power budget.

Calculate the link's power margin and distances when planning your fiber-optic cable layout. This will ensure that fiber-optic connections have sufficient signal power to overcome system losses and satisfy the minimum input requirements of the receiver for the required performance level. The power margin (PM) is the amount of power available after you subtract attenuation or link loss (LL) from the power budget (PB).

When you calculate the power margin, you use a worst-case analysis to provide a margin of error, even though none of the parts of a configured system operate at worst-case levels. A power margin (PM) greater than zero indicates that the power budget is sufficient to operate the receiver and does not exceed the maximum receiver input power. This means that the link will work. A power margin (PM) that is zero or negative indicates insufficient power to operate the receiver. See the specification for your receiver to find the maximum receiver input power.

To calculate the worst-case estimate for the power margin (PM) for the link:

  1. Determine the maximum value for LL by adding estimated values for applicable link-loss factors. For example, use the sample values for various factors as provided in Table 2: the link is 2 km long and multimode, and the (PB) is 13 dBm.
    Table 2: Estimated Values for Factors Causing Link Loss

    Link-Loss Factor

    Estimated Link-Loss Value

    Sample Link-Loss Calculation Values

    Higher-order mode losses

    Multimode—0.5 dBm

    0.5 dBm

    Single mode—None

    0 dBm

    Modal and chromatic dispersion

    Multimode—None, if product of bandwidth and distance is less than 500 MHz/km

    0 dBm

    Single mode—None

    0 dBm

    Connector

    0.5 dBm

    This example assumes five connectors. Loss for five connectors: 5 (0.5 dBm) = 2.5 dBm.

    Splice

    0.5 dBm

    This example assumes two splices. Loss for two splices: 2 (0.5 dBm) = 1 dBm.

    Fiber attenuation

    Multimode—1 dBm/km

    This example assumes the link is 2-km long. Fiber attenuation for 2 km: 2 km (1 dBm/km) = 2 dBm.

    Single-mode—0.5 dBm/km

    This example assumes the link is 2-km long. Fiber attenuation for 2 km: 2 km (0.5 dBm/km) = 1 dBm.

    Clock Recovery Module (CRM)

    1 dBm

    1 dBm
    Note:

    For information about the amount of signal loss caused by equipment and other factors, see your vendor documentation for that equipment.
  2. Calculate the (PM) by subtracting (LL) from (PB):

    PB– LL = PM

    13 dBm – 0.5 dBm [HOL] – 5 (0.5 dBm) – 2 (0.5 dBm) – 2 km (1.0 dBm/km) – 1 dB [CRM] = PM

    13 dBm – 0.5 dBm – 2.5 dBm – 1 dBm – 2 dBm – 1 dBm = PM

    PM = 6 dBm

    The calculated power margin is 6 dBm. This value is greater than zero, indicating that the link has sufficient power for transmission. Also, the power margin value does not exceed the maximum receiver input power. See the specifications for your receiver to find the maximum receiver input power.