How do I plan a PTP 820G 1+1 link with unit redundancy (external protection)?

PTP 820G 1+1 with Unit Redundancy (External Protection)

Read (and become familiar with) the following documents:

(search for “unit redundancy”)

  • PTP 820G Technical Description
  • PTP 820G User Guide
  • PTP 820G Release Notes

The network designer should be comfortable with LAG, LACP, etc.

Please note that there are protocols that unit redundancy does not support—this is why the network designer needs to consult this documentation.

The picture above shows both optical and electrical options in one picture—you don’t need both at the same time!

Starting with the throughput and availability requirements, plan the link as if it were a PTP 820G 1+1 link.

In addition to adding two PTP 820G chassis to each link, here’s what you need to consider:

  • Separate antennas at each end (space diversity, for example) or shared antenna at each end?
  • If shared antenna, the usual asymmetric or symmetric coupling?

All of this is “normal” PTP 820G 1+1 planning.

The next few items are new for PTP 820G unit redundancy.

  • TDM type T1 or E1? If the link is protecting TDM, add two of the following, per link: (This will protect up to 16xT1/E1. If the link needs to protect more than 16xT1/E1s, each chassis needs to be cascaded.)
    • C000082L154A          PTP 820G TDM Protection Y cable, 0.6m,120 ohm
  • Electrical or Optical protection?

In other words, how does the data arrive from the external switch to the two PTP 820G chassis? Straight through or via a protection Y cable? Via a copper Ethernet cable, or an optical Ethernet cable?

ELECTRICAL

If you want electrical protection, you can run two Ethernet cables (one from each chassis) to your external switch at each end of the link.

If you want electrical protection with a Y cable, add the following quantity two (2) to the BOM, per link: 

  • C000082L153          PTP 820G Fast Ethernet Protection Y-cable, 1.34m, Cat5E

Note that the electrical protection Y cable provides a single interface to your external switch, but it limits the link speed to Fast Ethernet (or 100 Mbps).

OPTICAL

If you want optical protection, you can run two fiber optical cables (one from each chassis) to your external switch at each end of the link. Add the following quantity four (4) to the BOM, per link:

  • N000082L059 PTP 820 SFP Optical 1000Base-LX,EXT TEMP
  • N000082L139 PTP 820 Optical CABLE,SM, 30m
  • N000082L147 PTP 820 Fiber Adapter

If you want optical protection with a Y cable, add the following quantity four (4) to the BOM, per link:

  • N000082L059          PTP 820 SFP Optical 1000Base-LX,EXT TEMP
  • N000082L139          PTP 820 Optical CABLE,SM, 30m
  • N000082L146          PTP 820 Fiber 1+1 Splitter, SM
  • N000082L147          PTP 820 Fiber Adapter

I hope this helps!

Dave

1 Like

Ha!

A steely-eyed observer has just noticed that LINKPlanner populates the BOM with quantity two (2) dual modem chassis.

You can double the number of these chassis, but that's not really needed.

Replace the dual modem chassis in the BOM with quantity four (4) of either of these, depending upon whether or not you're using E1/T1:

C000082M002 PTP 820G, Single Modem, Eth + 16 E1/T1
C000082M001 PTP 820G, Single Modem, Eth Only

With the four PTP 820G chassis, you’ll need to add quantity four (4) protection splitter cables:

  • C000082L155 PTP820G Splitter cable for protection and management, 1.34m,CAT5E

These cables break out the management ports and allow you to connect two PTP 820G chassis together in a unit redundancy configuration. They are similar to the PTP 820S and PTP 820C protection cables, except that the PTP820G protection splitter cables are indoor-rated.

If you're purchasing warranties, you'll want some of these as well:


AR-E1PT82M1-WW PTP 820G IDU (Single Modem) All Risks Advance Replacement, 1 Additional Year
AR-E2PT82M1-WW PTP 820G IDU (Single Modem) All Risks Advance Replacement, 2 Additional Years
AR-E3PT82M1-WW PTP 820G IDU (Single Modem) All Risks Advance Replacement, 3 Additional Years
AR-E4PT82M1-WW PTP 820G IDU (Single Modem) All Risks Advance Replacement, 4 Additional Years

EW-E1PT82M1-WW PTP 820G IDU (Single Modem) Extended Warranty, 1 Addl Year
EW-E2PT82M1-WW PTP 820G IDU (Single Modem) Extended Warranty, 2 Addl Years
EW-E3PT82M1-WW PTP 820G IDU (Single Modem) Extended Warranty, 3 Addl Years
EW-E4PT82M1-WW PTP 820G IDU (Single Modem) Extended Warranty, 4 Addl Years

AR-E0PT82M1-WW PTP 820G IDU (Single Modem) Upgrade to All Risks Adv. Replacement during Std Warranty

I hope this helps!

Let me know if you have further questions!

Dave

Hi Dave

Can I plan a all indoor [PTP820G+RFU-A]  2 x (1+0) Unit Redundency with single ploarization antenna? please refere to attached photo? Thanks.

Eric

Yes.

Dave

:)

To plan this in LINKPlanner, select PTP 820i with RFU-Ae (or Aep, depending upon the band) and you'll see that 2x 1 + 0 Unit Redundancy is an option.

Please let us know if this doesn't answer your question.

Dave

Hi Dave,

Thanks.

Eric Wang