School Network Re-Structuring

[philuptagus]

Hi,

I have been asked to re-structure a small residential high school's network, due to the fact that the residents' (100+ students) bandwidth, at times, is slow, and the current network setup allows them to use (without permission) administration bandwidth and 'steal' IP addresses. Also, it compromises security. I must add this is a college preparatory high school and our students are talented and gifted, so their computing skills can test the most talented IT Professional.

To give you a better picture of the layout of the physical campus, there are two buildings separated by parking lot; one is the dorm and the other is where classes are held and the location of the administration building (approx. 40 staff with computers). Both buildings are wired for networking.

I was asked to start with the dorm, since this is where most issues are. Before I began, I was told our internet source is a T1. So let me give you a visual of what I saw when I went to the wire room:

I located the "pipe" and from it were 12 optical cables (orange) leading to an optical box. When I opened the box, I could see (inside) all 12 optical lines connected to internal connectors. Now I closed the box with the knowledge that all 12 optical lines from the "pipe" are connected to 12 separate connectors inside the box. Looking outside the box I see 12 optical connectors (assuming 6 pairs, for RX/TX). The top two (pair) connectors on the box have an optical cable (orange) connected to a media converter (Allied Telesis ATFS201). [Let me add, for the record, that the next two (pair) connectors go to our phone system, an old PBX]. From the media converter there is a single RJ45 Cat5 cable connected to a switch (tier 2 port 21 to be exact). There are 10 of these switches, stacked and all are HP Procurve 2524 J4813A. These 10 switches are connected (100+ Cat5 cables) to the top rack which has 10 patch panels and they are all Sprint 449257 (manufactured in 1996 and are now discontinued). On the back-side of these patch panels are the "punch style" wire connections. So each cable is connected individually by the 8 wires within a Cat5 UTP cable (the RJ45 connecter is cut, exposing the 8 wires and connected to the back of these patch panels). So the Cat5 cables lead from the back of the patch panel, up several pipes to the dorm rooms.

Now that you have a picture of what I am facing, I have a question or two. The T1s I've encountered before had 24 wires. Have any of you seen our type of connection before (12 optical wires)? If I purchase more media converters, or a larger scaled one, can I utilize the remaining connectors from the optical box, create subnets (approx 4) by connecting the Cat5 cable (from the media converters) to routers and connecting a router per subnet (switched)? Also, I would like to factor in a server, preferably an SBS 2003 so I can manage the network. How would you all tackle this? Oh yes, other than re-crimping the jacks back on the existing Cat5 cables (from the dorm rooms that attach to the back of the patch panels) do any of you see any harm uninstalling (trashing) the patch panels and just using the switches? This would eliminate half the wiring (which, by the way, is a crazy mess). I'll work on the mess later.

Thank you all for your time and I look forward to reading your thoughts and ideas. Also, please refer to the attached network diagram I created.

 

[ITG Tech]

Your description of the back of the patch panel is a bit unclear. The correct way for structured cabling is to use the patch panels. The Cat5 cables need to be punched down correctly though. The individual wires within the Cat5 cable should only be exposed about ½ inch and maintain the wire twist if possible. Do you have a photo of the punch down area? Is the patch panel labeled to identify which cable goes where? I would keep the patch panel as it is an integral part of a structured cabling system. While electronically the patch panel may just be another place for failure, its real purpose comes in managing the network. Having a cable permanently connected to a dedicated patch panel port that is clearly labeled as to where the other end goes lets you troubleshoot and isolate problems.
If installed correctly a patch panel can be very useful in the network management. You can with the use of patch cords connect the end user’s jack to the correct switch or other network components as needed. You can do all this with out a patch panel but with 100 separate Cat5 cables all bundled up, you are really looking for a lot of frustration constantly trying to figure out which cable goes where. Even if the individual cable is marked with a sharpie, it is still very aggravating to pick up each cable and try and read the ID.
The orange fiber optic cable has 12 strands is this correct? Or is there 12 orange fiber optic cables and each one has 12 strands? The pipe that contains the orange cable is connected between? Is the fiber optic cable connecting the Admin building and the Dorms? Without more information, I would say that the unused strands are just spares. You can add media converters to them, but what is the source of the signal. Basically you need to know what is on each end of each cable/strand. Most fiber optic cable that I have worked with is also color coded much like the cat5 cable color code but not exactly. I will re-read your post to make sure that I better understand what you are asking, but I think you will need to supply a little bit more information describing the connections at each end of your cables.

 

[ITG Tech]

follow-up:
I have been asked to re-structure a small residential high school's network, due to the fact that the residents' (100+ students) bandwidth, at times, is slow, and the current network setup allows them to use (without permission) administration bandwidth and 'steal' IP addresses. Also, it compromises security. I must add this is a college preparatory high school and our students are talented and gifted, so their computing skills can test the most talented IT Professional.

Consider setting up a managed switch with VLANs for the separate areas.

I was told our internet source is a T1.

Verify the Internet source. Locate the Demarc and or contact the clients ISP to get the details.

I located the "pipe" and from it were 12 optical cables (orange) leading to an optical box. When I opened the box, I could see (inside) all 12 optical lines connected to internal connectors.

There should be two fiber optic boxes one at each end if this is the cable connection between the Admin and Dorm. Each box besides connecting to each other connects to something else at each end. Both ends use media converters. Usually a RJ45 connector is connected to the media converter from the Source such as a switch or router. The same applies at the other end. The RJ-45 comes out and connects to a switch at the other end for distribution. Is this what you have?

The T-1 that you are describing may be a fractional T-1 with a channel bank. A full T-1 has 24 channels (23 for phone lines) these are combined for data (increased bandwidth). Noramally a T-1 comes from the Central Office (CO) and terminates in a smart jack. From the smart jack, it goes to a channel bank or CSU/DSU or other device. The channel bank breaks the multiplexed signal down into separate channels of bandwidth. You need to investigate and find out exactly what you are dealing with.

I don’t know if any of this helps, but do some more homework and get back here and let us know what you found. The forum will help you in this project.

 

[angry_geek]

I agree with the more info request. However, here are a couple of suggestions. First, there must be far more than 100 cables. 10 of those switches gives you 240 ports. Same goes for the patch panels which you absolutely want to leave in place. Patch panels either work or don't. Doesn't really matter what brand they are, as they are just dumb pass-through blocks. They will come in handy, especially with that much cable to manage. I would first see if there is any unnecessary hardware in there and remove it. If there are only 100 cables, then half of those switches can be removed. That model is a good managed switch, but you need to study up on them to set them up correctly. I wouldn't use SBS 2k3. I think you would be better off with a good Debian box with several nics to manage your network. I've used IP Cop to manage, but not on a network that size. ACG has a lot of experience with Debian; maybe he can suggest something. A simple stand alone router isn't going to cut in that situation unless you go with an expensive Cisco; something similar to the old 2600 series. A good Debian box will cost will half as much and be a better manager of the network.

 

[NYJimbo]

If you got a 12 strand siecor cable going to a breakout that's 12 T1's, not one T1. I doubt all of the glass is lit, but you can find that out by tracing wiring out the breakout to smartjacks or other terminating equipment. Each T1 fiber can do 24 channels or can be broken down to about 23/24 copper pairs analog. Maybe you should hire someone to at least go over the fiber parts and then you take over the copper or client-side stuff.

 

[philuptagus]

Hi All,

Thanks for getting back so quickly. I apologize for not sending actual pictures before, but I have included them on this post. Pictures include: the rack showing both the patch panels (top 10) and switches (bottom 10), close-up of optic cables, box and them leading to the media converter, and the back of the patch panel.

Unfortunately our IT Director and I are having a little trouble with the IT Director we share the administration building with. Two schools (us and the local high school) share the admin building, but we own the dorm building. We have been requesting to see the wire room in the admin building, but as of yet, nothing. We find this very frustrating because we (and as you all pointed out) not only lack the information needed to build diagrams, topologies, etc., but also want to know where the source is coming from and how to build, remap, etc. My IT Director will be speaking to our Executive Director beginning of the week to insist we get access to everything, but until then I apologize for not including that piece of the puzzle. If I were to assume how the network is setup, I would say the previous IT Director made two LANs, one for the local high school and one for our school (the admin building AND the dorm share one LAN). If I am correct, this would explain why our students can steal IPs and view admin’s network.

But what we do know is the dorm network is flawed and we are trying to get it under control. Imagine 130 teenagers with internet access with no protocols. Since we do have 100% access to the dorm’s wire room, I thought this is where I’d start. At least have some protocol in place to limit excessive bandwidth use and improper web surfing etc. Fortunately the students are away for the summer, so we have a little time (mid-August)

I thank you all for being patient with me as the doors slowly open to my network problems. Please share any other thoughts you may have and let me know what you think about the network’s hardware (pictures), this may help you understand.

Thanks again.

 

[angry_geek]

I can say this much. The back of the panels look great. I wouldn't touch those. The front of the rack, however, I don't envy you. Look forward to reading more info when you post it so we can try to help a little.

 

[NYJimbo]

I thank you all for being patient with me as the doors slowly open to my network problems. Please share any other thoughts you may have and let me know what you think about the network’s hardware (pictures), this may help you understand.

Thanks again.

Let me ask you two questions.

1) Looking at those three pictures, how much of it do you TRULY understand?. Can you produce a report for someone explaining what is going on in each photo ?

2) How much of that hardware and wiring do you know how to run ANY diagnostic test yourself ?

 

[ITG Tech]

I concur with what angry_geek and NYJimbo has said. Leave the back of the rack (punch down) alone. The front could use some cable management for the patch cords, perhaps color coding too.
You need to be clear in your mind and be able to explain to others what and where each cable goes and what it is for. Continue gathering your information and building the topology mapping and device connectivity understanding.
Looks like you have a real good project to work with. I look forward to seeing more on this.