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
