SV9100 - 19" 6-Bay version or the 9.5" Plastic 3 bay with 3 bay expansion

[chrismec]

Hi all, we are soon to be getting an SV9100 system which will be installed across several sites. Most sites can fit within 6-bays, but some will require 8 or 9 bays. For the physical hardware there are a couple options, there is a 19" metal 6 bay chassis or you can combine a 9.5" plastic 3 bay chassis with a 9.5" 3 bay expansion module to get a functionally equivalent 19" rack mount 6 bay chassis. The interesting thing about combining the two smaller 3 bay modules to get a 6 bay chassis, is the MTBF specification for this configuration is 10 years as opposed to the 7 years with the 6 bay chassis, which is an increase by a factor of nearly 1.5. So not totally insignificant. The plastic chassis configuration has an arched top, which makes the rack mounting vertical for some reason and the chassis stacking not ideal for systems requiring more than 6 bays. These mounting & stacking issues kinda steer the ship away from the plastic chassis configuration, but if the NEC specs are accurate, it is difficult to ignore the almost 50% average longer runtime of the plastic chassis config. I was hoping to hear ya'lls thoughts.

 

[CoralTech]

You are over thinking it. The smaller plastic models also don't have an easily replaceable power supply either. The cost of a 6 bay chassis is insignificant to the mounting space you save by going with the rack mounted 6 bay chassis. Also all the 6 bay chassis are interchangeable so having one on hand means you cover everything. Standardizing = less headaches. The cost for a spare cabinet is virtually nothing. Not only that you can also replace the cabinet and take the other cabinet and replace just the power supply rather easily setting yourself up nicely. Also the plastic cabinet does NOT have cooling other than convection. Personally we only use the plastic ones for really small jobs that require wall mounting.

 

[CoralTech]

As a side note you have asked a LOT of really simple questions that the people installing your system should be telling you. I hope you aren't doing this by yourself or they are letting you dictate some really bad decisions just trying to sell you a system. Just curious.

 

[chrismec]

For most of our sites, a wall mounted system would be more appropriate anyway, where the old wall mounted system would be removed and replaced with a new wall mounted system. Chassis interchangeability would be essentially the same with the smaller ones, but I understand your point. An easily replaceable power supply is good, as some tech's might not be as willing to dive in and swap guts as others might be. I'm betting that active cooling was necessary on the 6 bay chassis precisely because it is horizontally rack mountable and can be stacked right on top of each other. That configuration tends to build up heat rather quickly. I'd be willing to bet that the additional heat experienced by rack mounted systems is the reason for the reduced MTBF rating. Dont get me wrong, I'm not necessarily advocating the smaller chassis and am personally leaning towards the 6 bay chassis because it does have more flexible mounting options, I was just looking for additional opinions from other folks. Especially when you have a nearly 50% increase in MTBF specs with one over another, I wanna know what the deal is. For me personally, I am not new to phone systems, I've been working with them for over 25 years, but they were never my primary responsibility. I am new to NEC however and I come here begging for your much appreciated advice specifically because contractors/sales/installers misrepresent system capabilities upfront and during the process due to various reasons. I do really appreciate your advice CoralTech! Thank you

 

[CoralTech]

Not seeing the 50% MTBF. The 6/12 bay cabinet can also be wall mounted on the wall. I have yet in 20+ years installing these UX-SV seen a power supply failure. I mean besides water and lightning. Active cooling is also better in warm environments as well. The more standardized you go the better your Netlink will work. I have never mixed cabinets because of how Netlink functions and the duplication of the database across the network.

 

[chrismec]

I found the MTBF information in the UNIVERGE SV9100 System Hardware Manual (version 12.1) page 2-41 (p.147). It actually shows the 6 bay chassis to be 6.49 years with the B & E chassis at 10 years. I'm glad you mentioned Netlink in this and the other post. I'm still waiting to hear back from the contractor what method of interconnection they will be using. I assumed Netlink but am probably wrong on that because we require independent site operation in the event of network failure and from my understanding a Netlink config will go into some kind of limp mode if connections to the main/backup master station is down. That is something I'm trying to drill more into in the docs...

 

[CoralTech]

Netlink will re-boot and attempt to recover on primary then secondary sites. If not the system will come up and work in survival mode (local lines etc). Netlink makes the whole system work as one big system. CCIS is where you are basically tying the systems together in a more traditional way. Each site is independent for the most part. It still can have BLF and centralized VM if you want.

Netlink one big system you program from one system.

CCIS you program each system.