I evaluated several campus PON project on both vendor/provider and customer sides over the last 5 years.
PON was designed as a last-mile technology for _operators_ to cover huge areas and save on OPEX - that's the usual vendor's mantra. GigE usually takes two fibers to deliver; GigE aggregation requires an Ethernet switch you need to power and maintain - "many points of failure" argument. PON only takes one fiber, splitting a PON signal is done by a cheap passive optical splitter which, once installed, lasts forever. Correct cost comparison between PON and Ethernet is pretty difficult. First, the cost of the actual network _equipment_ (switches, routers etc.) for an Access network (tens of thousands of subscribers) is nothing compared to the civil works - trenching, cabling, permits etc. Second, CPE cost is the most sensitive on that scale. $5 cheaper CPE saves more money than a $50k cheaper OLT. Without scale benefits and (assumed) OpEx reduction, PON projects are usually significantly more expensive. Now, to the projects. I have never heard of seen PON on a DC level. As for the campus, none of the projects took off, and here is why: - PON equipment is proprietary. An OLT (PON hub) from vendor X works only with ONTs from the same vendor. Every other vendor claims there is "some interop" but none was able to do demonstrate. - PON infrastructure - a passive fiber tree - is a) proprietary b) not flexible. You can make any physical topology of your usual p2p fiber segments but a tree is always a tree; plus PON usually requires green APC (angle polished) connectors. - PON US/DS bandwidth allocation is asymmetric. Training, maintenance and support are important, too. Ethernet is ubiquitous, PON engineers are a bit harder to find. Proprietary nature of the product implies that a Huawei PON would look and feel somewhat different than, say, Calix PON hence the knowledge is more vendor-specific. Also, nobody likes vendor lock. If an Access Ethernet switch fails, you can - potentially - replace it with another fairly easily. PON ONT of different vendors may all come from the same OEM like Cambridge but the firmware is different. What did I miss?... Ah, the usual cabling There is a more sophisticated WDM-PON. Ericsson and Teradata had it in development, Infinera offers it as iAccess product - but I haven't tried that yet. Overall, it really depends on a project (getting all the MTBF data and calculating the failure cost was quite a task) but I personally can't see any PON benefits over Ethernet for either campus or DC even in the midterm. >From my personal experience, flexibility with cables plus cheap CWDM filters and colored optics can do magic on the campus level. Stas On Sat, Jan 21, 2017 at 10:44 AM, Kenneth McRae <kenneth.mc...@me.com> wrote: > Greeting all, > > Is anyone out there using PON in a campus or facility environment? I am > talking to a few vendors who are pushing PON as a replacement for edge > switching on the campus and in some cases, ToR switch in the DC. Opinions > on this technology would be greatly appreciated. > > Thanks, > > Kenneth
