> I looked at your network diagram. Try checking the configuration of the > Ethernet ports on the firewall and the Asterisk box. Make sure they are > set to auto-negotiate and not set to a fixed speed and fixed duplex. > I have found in the past that if one end of a link is expecting auto- > negotiation (as the switches probably are) and the other end is expecting > a fixed configuration, things can degrade to half-duplex trying to talk > to full-duplex, resulting in lots of collisions and packet loss when there > is any kind of significant traffic. > > Your description would be consistent with the firewall introducing lots of > LAN collisions when busy, in the central gigabit switch, even if the VoIP > traffic isn't passing through the firewall.
Also, check the wiring. Check each individual RJ-45 jumper, *and* the in-house wiring, with a proper tester that can verify that the individual pairs are hooked up correctly. I've seen all kinds of hell occur, in situations where somebody used telco-type RJ-45 connecting cables, in place of proper Ethernet connecting cables. The problem is this: in a telco RJ-45 cable (such as was/is often used for proprietary telephone systems) the individual wires are either not in twisted pairs, or are twisted-pairs in a 1-2 3-4 5-6 7-8 arrangement. These work fine for analog connections. They're latent-death-on-wheels for Ethernet. Ethernet only works well if you connect the pairs as a 1-2, 3-6, 4-5, 7-8 arrangement, because this is how the signals are sent electrically. Using the correct connections ensures that the signals on each pair are "balanced" electrically - that is, the two wires in each twisted pair are carrying equal-but-opposite currents for the two sides of an individual signal. This minimizes electrical coupling between pairs, and thus minimizes crosstalk. If you use a telco-style cable (these are often black, and flat), or if you use what looks like an Ethernet cable but which had its wires "punched down" to the connector in the wrong pairing, things go very badly indeed. One twisted pair might be carrying one TX signal and one RX signal. This pretty much *guarantees* terrible cross-talk between the two. The symptoms of this can be as was related... the connection appears to work OK under light load, when there's usually traffic flowing in only one direction at a time. However, when you put a bidirectional load on the connection, the signals going from A to B and from B to A cross-talk with one another, leading to a very high rate of corrupted/dropped packets on the network. This will often show up in the end device's Ethernet packet statistics, if you can get to them... look for a high rate of dropped or "bad" packets, FCS (frame sequence check) errors, etc. I've seen a fair number of cheap "Ethernet" cables that had been manufactured wrong. You should see a color pairing such as http://www.hardwaresecrets.com/how-gigabit-ethernet-works/ indicates - pins 4 and 5 are a pair (blue, and white-and-blue), and the next-outer pins are also a pair (orange, and white-with-orange). If you see a pattern such as "white-with-green, green, white-with-blue, blue, white-with-orange, orange, white-with-brown, brown" where there are four color-matched pairs of wires next to one another, you've got a bad cable. The same error can occur when building wiring is "punched down" to the RJ-45 jacks. A good Ethernet cable-pair tester can spot such things pretty quickly. -- _____________________________________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- Check out the new Asterisk community forum at: https://community.asterisk.org/ New to Asterisk? Start here: https://wiki.asterisk.org/wiki/display/AST/Getting+Started asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
