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Mystery drop & fishing firewalls (fire-stop) in townhomes

Discussion in 'Switches, NICs and cabling' started by ilija, Sep 13, 2017.

  1. ilija

    ilija New Around Here

    Sep 12, 2017
    Forgive me if I provide too much or too little detail. In a nutshell, I'm trying to place my router in a different location in a home partially pre-wired for ethernet, but the jacks aren't working as expected.

    I live in a two-story townhouse that was wired initially by at&t U-Verse (I am not the initial owner). There is a communications panel with a ridiculous number of wires in the garage (all photos with DM prefix), which the last service rep that came out said was the demarc for them. I believe it's the wire marked Term. or Bldg in the photo. He marked another wire with a "?" for me, because he couldn't figure out where it went.

    Inside the home proper on the upper floor, there is one one wall plate with one jack labelled internet that gets plugged into the WAN port of a Arris 5268AC, and another jack for phone (which I've never used). Two feet from it is another wall plate with a single (blue) RJ45 jack wired using 568A (LAN1, to make this easier). About 45 feet opposite this (other side of room), is another blue RJ45 jack (LAN2) fairly close to a coax term (separate wall plates). On the ground floor, almost directly under LAN1 I have a third pair of wall plates. One with a blue RJ45 (LAN3) and telephone jack, and another with a coax term. The wall plate with LANA3 was wired 568A-ish for data with the blue pair going to the phone jack instead. Every jack mentioned in this paragraph resides in a firewall, where the outlet boxes themselves have been coated with fire-stop putty prior to drywall going up. The three RJ45s as described are the only three that I have ever seen in the entire home, and all of the ethernet cabling is 5e (same with jacks).

    The phone might actually be terminated in the attic (there's some wire labelled phone up there). The home also had a wired alarm system as well as some form of link to a common fire sprinkler/notification system (shared by the townhouses in building). I mention these because of the demarc so many flipping cables.

    I assumed LAN1 would connect to LAN3 which is about 14 feet below it. Using a cable tester, it seems to be open. However, a cable tester did show LAN1 and LAN2 to be in sync. LAN3 at some point I'm positive was working because my media center equipment (TV, game console, set-top box, etc.) were using it. The problems began when I tried plugging in a router to LAN3 and it utterly failed to do anything (but the router could feed a signal into it from LAN1. LAN1 to LAN3 shows open for all wires.

    Trying to run fish tape through the wall, I ran into two problems: a) the fire stop putty is a bit difficult to manipulate, and b) trying to do it from upstairs to downstairs end exactly how far it is from outlet box to floor. I'm afraid the floor goes between the wall joists and that only a small hole was cut for ethernet cable.

    I am at a complete loss as to how to even begin diagnosis and/or repairing this. Some possibly stupid questions I have are:

    1. The at&t tech had some form of contactless continuity tester that could be used on live circuits without unplugging anything. Is there are reliable and reasonable affordable version of this type of tool, especially one that doesn't need to be plugged in at both ends?
    2. Does anyone have any experience and/or recommendations for fishing cabling through a firewall (fire-stop wall)?
    3. Can a 568A cat 5e cable work with 568B cat 6 jacks?
    4. Can anyone explain what's going on in the anchor photo? The cable seems to be looped around the screw post in some strange way.
    5. Is there some convention at&t follows for cable colors? Other than black for coax, I'm getting mixed signals for the demarc photos.
    6. Is it safe to assume splicing ethernet cables does not work like it does with common 120V wiring? I ask because of the funky types of connections going on in the demarc box, LAN3, etc. I was afraid somehow they spliced LAN2 and LAN3 together and that LAN3's connection somehow broke.
    My apologies for unloading all the questions but I'm at my wits' end and wanted to take a DIY approach.

    Attached Files:

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  3. System Error Message

    System Error Message Part of the Furniture

    Oct 14, 2014
    you can easily connect things, as long as its a patch panel it makes things easier, otherwise you can use a switch but it must be a managed switch. Your router will need at least 2 ports so make sure there are at least 2 sockets for the router, connect WAN to modem which can be anywhere, connect LAN to switch.

    If you have a firewall it depends on the type of firewall, if it is capable of inspection on WAN than place it on WAN but not all ISPs use protocols that the firewall can inspect which would then require a router to send packets to firewall for inspection (a bit like with mikrotik and suricata).

    You can splice ethernet cable wiring. rj 45 and rj 11 are compatible and phones can share the same cable/line, but do not put the same ethernet cable among PCs, this is because all 8 pairs of ethernet are required for gigabit speeds. So ethernet is point to point, cable cant be shared (shouldnt really). Phone cables can be shared like electrical lines, require only 2 pairs (but its better to wire 4 pairs) and compatible with rj 45 if 4 pairs are used but only if the cable is going into a phone and not a computer.
  4. ilija

    ilija New Around Here

    Sep 12, 2017
    Thanks for the response! If the portion above was in response to my second question, I am referring to a literal fire-rated wall (firewall), not the the technology term based upon it. Meaning one of these:

    Thanks again!
  5. degrub

    degrub Very Senior Member

    Dec 21, 2015
    by code, any penetration of a fire stop has to be sealed with the intumescent caulk (firestop caulk).
    So if you open a hole in it you have to go back and restore the seal.
    The cable would also likely have to be rated as non-propagating or self extinguishing. i am not as familiar with that section of the code. Perhaps plenum rated cable would be allowed.
    ilija likes this.
  6. thiggins

    thiggins Mr. Easy Staff Member

    May 18, 2008
    It looks like you have a real mess on your hands, hacked together by someone who did not understand data networking.

    The photos of the "DM" box look like all the CAT cable runs are just spliced together and probably connected to the phone landline, if you have one. This will never work for Ethernet.

    Each cable needs to "home run", i.e. run directly to a central point, where they plug into an Ethernet switch. Unlike phone wiring, you can't daisy chain from one jack to another.

    I suggest reading through this series to understand the basics of what you need to do.

    If you need either landline phone or alarm, you first need to determine which, if any, of the cables in the box o' mess are used.

    If you don't need a working landline or alarm system, I would start by removing the splices from all the CAT5 cables. You'll need to do this to trace connections.

    The sniffer the tech was using still requires a signal generator to be clipped onto one end of the connection you are trying to trace. If all the cables are connected together, you can't trace them.

    There are plenty of cable testers around. You can probably pick up one in the Electrical dept at Home Depot/Lowes/ etc.

    I don't know that you need to fish any new cables. You just need to trace and properly connect the ones you have.
    ilija likes this.
  7. MichaelCG

    MichaelCG Senior Member

    Jan 4, 2017
    Central US
    Firewall - I have on suggestions on how to get through that fun. That is something I probably "should" pay more attention to at my own house, but not being in a shared space residence, we don't have firewalls to deal with...although we do have some fireblocking things we "should" be doing.

    LAN3 - It can't be connected to LAN1 if LAN1 is connected to LAN2.
    If LAN1 connects to LAN2, it cannot also connect to LAN3. There must be another cable somewhere you haven't identified. Generally in older U-Verse, they will either use Cat5e or COAX to connect the STB back to the RG. The fact that the blue pair out of LAN3 goes over to the phone jack means that LAN port is unlikely to be functional...at least not for 1Gpbs it won't be. It may still work for 100Mbps.
    Affordable? That depends on your definition of that. You can buy toners for $50'ish from various places.
    Sorry...not something I have had to deal with. I have only done open commercial and stuff in my house which didn't cross any physical firewalls.
    I don't really remember the differences between the two...I haven't had to care about that for many many years. I "think" it will not work if it is a single cable to the jack. But if you use a 568A cable on each side of the 568B jacks, it may work out.
    Yes, they installer was trying to not lose the cable back down in the wall, so he looped it around the nail post which is not great for keeping 5e or 6 in spec being bent that tightly.
    Doubtful there is a standard other than what they happened to have on the truck.
    Correct...you cannot splice Ethernet Twisted Pair. It is a point to point type cabling.
    ilija likes this.
  8. CaptainSTX

    CaptainSTX Very Senior Member

    May 2, 2012
    This isn't going to be a simple project. You are either going to have to terminate and trace the cables yourself or pay a technician to do it.

    First, identify the cables that are for the alarm system and sprinkler notification. You are either going to have to find the senders and identify what cables they used then mark them and leave them alone. Your building's management company may be able to put you in touch with who maintains those systems and they can help you with that part.

    Second look at the orange and white cables and see what the cable type is listed on the jacket. The cables you want should say Cat 5 or Cat 5e. You need cables with 4 pairs (8 wires ) for Ethernet. You can get by with only 2 pairs however at best you will get 100 Mbps.

    Since you are starting with a mess I recommend that you terminate or reterminate all cables that you want to use with new keystone jacks 568B (easy to do no tools required ) and in your wiring cabinet terminate all cables with RJ 45 male jacks. (Harder and more frustrating ). If you use a Platinum tool and their clam shell jacks it is some what easier. Any splices in cables you plan to use need to be eleiminated. Jelly bean splices you show in your pictures are for telephone wiring. All runs need to be straight point to point no loop through.

    Once you have all the cables identified take a pinning continuity tester and begin tracing each cable and marking it. What is critical at this step is continuity. It is highly probable that some of the cables will show, open pairs, reverses, etc. As I said earlier terminating Ethernet cables is frustrating so you can expect to have to reterminate some cables.

    Once you have identified all your cable runs you can start designing you network. You can either install a simple switch in your wiring cabinet or a patch panel.

    As for pulling cables through firewalls hire a local electrician that will have the tools to drill through the firestops or will tell you that code will not permit that type of wall fish. Normally when you penetrate fire walls you have to seal the penetration after the cable/ wire has been run. This would mean cutting access points in the wall at every fire stop penetration to seal the hole.

    Good luck! Getting an in house Ethernet LAN working is well worth it because it still is the gold standard of connectivity.
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