• Stuttering Audio on VOIP phones when first answering a call slow and fast audio


    In this case, Iam assuming you have verified the firewall on either side, and the network conditions are not an issue (eg. no packet loss, no crazy jitter and normal latency). In some phones such as Grandstream or on your PBX, make sure you do NOT use the "adaptive jitter buffer" or similar settings. If possible disable that or change it to "fixed". If you do, you may wonder why when you first start a call the user cannot hear you or the voice s........
  • Using Cisco CME Router with Asterisk as a dial-peer


    #Remember that you need a valid gateway IPunless the Asterisk server is on the same subnet and LAN Set Valid Gateway IP (if you don't have one already) ip route 0.0.0.0 0.0.0.0 GATEWAYIP Enable VOIPTrust voice service voip ip address trusted list ipv4 0.0.0.0 0.0.0.0 sip Set Credentials For Asterisk and Register To Asterisk sip-ua........
  • Cisco CME How To Configure SIP Trunk VOIP


    This is how we configure outside PSTNaccess or dialing through another SIPtrunk. Beware that this a simplistic example that neglects most security including SRTP First you'll need to be in config mode: Step - 1 Enter Voice Service VOIP security options There are more options but for now we'll just focus on security/allowing connections to and from our phones and the trunk. Router(config)#voice service voip ........
  • Grandstream Phone Vulnerability Security Issue Remote Backdoor Connection to 207.246.119.209:3478


    Have you checked your router/firewall logs and disconcertingly see connections to an unknown IP207.246.119.209:3478 from your Grandstream VOIPphones? You're not alone and the Grandstream forums have discussed this issue. However, even their own staff d........
  • Juniper JunOS Command Overview and Howtos Switch, Router, Firewall Tutorial Guide


    Enable "cli" mode equivalent in JunOS cli Configure Mode configure So rather than going to the console on a Cisco switch and typing "enable" and then "conf t", the equivalent in JunOS is "cli" and "configure". How Do You Apply Changes You've Made? You can make all kinds of changes to the switch, but remember they are not........
  • Asterisk Does Not Retry When Authentication Fails


    When authentication times out that is one thing, but when it just fails like below Asterisk by default will not re-register until you the admin reload the sip or asterisk server: voipserver*CLI> sip show registry Host dnsmgr Username Refresh State&........
  • tftp Linux xinetd verbose logging


    It is much more useful to have meaningful and detailed logging from tftp to see what is or isn't happening especially for VOIPand other embedded device appications: Edit the file: vi /etc/xinetd.d/tftp Change the server line like this: server_args = -s /var/lib/tftpboot........
  • Cisco CUCM Unified Communication Manager Howto Guide and Tutorials


    Install Issues: How to Make CUCM iso /modify to work on non-VMWare machines like QEMU/Xen/OpenStack If you get kernel panic errors in VBOX usually disabling Nested Paging will fix the issue (thanks to Mark). ks_pre.sh error is caused by having the wrong VDX pattern (change it do sd per guide link above) and/or the wrong VMSpecs (Cisco req........
  • How Does Cisco CUCM (Cisco Unified Communication Manager) Work?


    Cisco's CUCM (Cisco Unified Communication Manager) is a system that combines voice, video, data and mobile products into a single unified management suite. At its core, the CUCMis like a "Super PBX" that controls the flow of all communications through an organization even single or multiple site deployments. Cisco's CUCMmakes communication more effective and simple through centralized management and unification of communications resources.........
  • ffmpeg Linux Mint download, compile and install howto


    #if you have nvidia make sure you install the nvidia-cuda-toolkit so hardware acceleration can be used wget http://ffmpeg.org/releases/ffmpeg-3.3.2.tar.bz2 tar -jxvf ffmpeg-3.3.2.tar.bz2 cd ffmpeg-3.3.2/ ./configure --disable-yasm install prefix /usr/local source path ........
  • Migrate Centos 7 from Single HDD to mdadm RAID 10 array:


    Done on Centos 7.3 very important as clearly based on older guides it was a lot easier and more simpler! Hint do not use grub2-install! If you have trouble booting after this check this CentOS mdadm RAID booting/fixing guide. One huge caveat if you are an oldschool user or sysadmin who has avoided UEFIbooting The nor........
  • Linksys / Cisco / Grandstream / Polycom PAP2T No delay in dialing recommended fast dial plan


    I modified the default to the following for faster local dialing for North American area codes: (*xx|[3469]11|0|00 [2-9]xxxxxxS0|[2-9]xxxxxxxxxS0|1xxx[2-9]xxxxxxS0|xxxxxxxxxxxx.) This is what I added to the above: "[2-9]xxxxxxxxxS0" so any 9 digit number is dialed instantly xxx-xxx-xxxx (the S0 at the end makes it dial right away). This makes dialing much quicker and is recommended. *No........
  • PAP2T Linksys VOIP strange ring problem


    The problem is that the default of most of these units is set for non-North American phones so the ring sounds like it cuts off and is not sequential. How To Fix the Issue Click on "Regional" and make sure you are in Advanced mode. ........
  • Sipura/Linksys VOIP Adapter How to Check your IP Address


    Dial **** Then 110# It will then say what your current IP address is.........
  • Asterisk VOIP Sipura/Linksys PAP2T Calls Not Being Received Solution


    This problem seemed to happen recently but was likely causing issues before where the phone(s) do not ring. Now there are a few reasons why this can happen especially if your adapter has DND mode enabled (disable it). However that wasn't my issue and Ionly figured it out the other day when by fluke if you're on the phone (making a call) then calls will come in. That's when Ifigured out the solution: This likely app........
  • Sipura / Linksys PAP/VOIP/SIP Adapter Issue Can't receiving incoming phone calls and you're behind a NAT router (99% of people)? solution


    Sipura / Linksys PAP/VOIP/SIP Adapter Issue Can't receiving incoming phone calls and you're behind a NAT router (99% of people)? 1. Login to the adapter. 2. Click on "Advanced" (location varies but usually somewhere on top) 2. Click on "SIP" 3. Scroll down to "NAT" (usually at the bottom). You'll find 2 columns with 4 rows of drop-down boxes (they'........
  • Country List Names in HTML Select From


    This is useful for developing a lot of applications, I'm putting it here to keep it handy for myself and hopefully others: Choose CountryCanadaJapanUnited StatesUnited KingdomAfghanistan........
  • gocr - free Linux OCR (Optical Character Recognition) conversion tool


    gocr works great and it's simple, just invoke it like so: gocr filename.png The output will be printed to the screen. My only complaint/concern is that even with standard terminal output (not scanned) from a printscreen, gocr does make mistakes by inserting extra spaces where they don't belong, mistaking letters for numbers etc.. but it's definitely enough to be readable and figure out what you're looking at. I haven't tested yet with scanned input........
  • VOIP/Asterisk/FAX Error Problems Solution NOTICE[11389]: rtp.c:1808 ast_rtp_read: Unknown RTP codec 100 received from


    NOTICE[11389]: rtp.c:1808 ast_rtp_read: Unknown RTP codec 100 received from I've found that trying several times may work, but I also read changing your Sipura VOIP adapter settings as follows helps (but it still fails for me sometimes): In adapter change the following under SIP/Advanced Codec to G711a from G711u Passthru Method from: NSE to ReINVITE FAX CED Detect Enable: Yes FAX CNG Detect........
  • Updated to Version 3.8 and can't login


    Updated to Version 3.8 and can't loginSSHD accepts my password but then hangs at "Last login: Wed Sep 13 21:30:02 2006 from" This occurred during a yum update after upgrading my release, installing the new kernel and rebooting. I got kicked out of sshd after seeing the following during yum update: telnet 100 % done 85/476 tux 100 % done 86/476 ntsysv 100 % done 87/476 rpmdb-redhat 94 % done 88/476........
  • Telus + 2Wire 2700 Router Horrible


    Telus + 2Wire 2700 Router HorribleWell first of all let me say this is the only router/switch that sometimes seems to crash/disconnect computers on the local network. This device also thought it would be smart to block VOIP packets coming from my Sipura ATA VOIP adapters so I disabled the [quote:cb89ba7bff]"Invalid TCP Flag Attacks (NULL/XMAS/Other)"[/quote:cb89ba7bff] option Then all of a sudden I couldn't get onto any web pages, the wireless........
  • Asterisk Queue Context Explained


    Asterisk Queue Context ExplainedThis was never explained in voip-info or any other site I read. It is understood you can escape to a context from a queue and how to specify it. [b:882f1e0aee] What is NOT mentioned is that the context= you specify within the queues.conf refers to a [i:882f1e0aee]context that exists in extensions.conf[/i:882f1e0aee][/b:882f1e0aee] This will save you headaches if you need to escape from the queue :)........
  • Using a Mac OSX DMG Image in Windows and Converting to Standard ISO Format use dmg2iso


    The dmg format is silly and annoying to work with, why couldn't Apple stick with the .iso standard? Anyway, there's an excellent Linux and Windows based tool to convert it back to a normal .iso Image called dmg2iso I'll only cover theLinux version although the Windows pre-built binary works the same way. Download dmg2iso here for free (from the author's website) It's just silly and doesn't make sense that Ubuntu doe........
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