North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: SONET ring questions
> 1) Bell Atlantic assures us that, because of the redundancy, we can > expect 100% uptime from the OC-12. I would like feedback as to > whether this is a realistic portrayal of the SONET environment. Assuming the primary and backup paths are not in the same cable anywhere (don't laugh, it happens), the chances of the OC-12 itself failing inside Bell land are tiny. (Of course, if your local loop gets assaulted by a backhoe, you're in trouble.) > 2) We have the option of using either single-mode or multi-mode fiber > OC-3 connections - what factors should be considered in selecting > the fiber media type. Single mode goes farther. Multi-mode is cheaper. If you've got relatively short cables, save some money and use multi-mode. If you're dragging fiber all the way across the building, or between buildings on a campus, use single-mode. > 3) Which routers should be used. The options are 3com NB-II's DPE+ > (dual CPU), Cisco 7200 series, or Cisco 7500 (each router will > have at least two 100Base-T LAN ports). OK, I know the 3com > suggestion is a loaded question for this list, but has anybody > used the 3com's in this capacity? We are a 3com shop that is > considering switching to Cisco - this is a significant decision > because switching will require us to continue to maintain the > existing 3com environment (~500 routers) and the new Cisco > routers. If you go Cisco, I'd recommend the 7500 series. The 7200 series won't handle two OC-3's and two fast ethers. You'll drop packets.
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