Authors Medium Mark Lindsey SMTS at ECG

Work Flows Up: Effectively Distributing Work on a Team of Engineers

Sometimes junior technical staff are starved for interesting work while senior staff are overworked This is Part 2 in my Series on Supporting/Managing Engineers If a team has lots of technical work to do, and only a few brilliant engineers available, how do you get work to the right people? In this article, I discuss methods for managing work in IT and technology teams, such as those doing Netw...


Mentoring Junior Engineers is Worthwhile

Most experienced professionals value the opportunity to mentor others; not so for some elite technologists To enable more people in a technical team to do work, more people have to know how to do it. But for many engineers, training doesn't come natural. This is Part 1 in my Series on Managing Engineers Is one-on-one training a rational activity, or just a feel-good strategy from the HR departm...


BroadWorks CDR Decoder

If you use BroadWorks with CSV CDRs, you're probably accustomed to reading these: 00255943365CF3FC1CF15820160404194616.3061-040000,ECG,Normal,+12296543428,+19125293400,Originating,+12296543428,Public,+12296543409,20160404194616.306,1-040000,Yes,20160404194624.106,20160404194650.684,016,VoIP,,3409,private,,,,local,Group,,PCMU/8000,216.128.52.5,fd390cb4-eb6d3d15-f8fb7fd2@10.23.6.217,,,,Hermes Com...


Polycom and Adtran AOS Geo-Redundancy Support

Background The Polycom SoundPoint IP SIP Phones and Adtran IADs are used for Hosted IP PBX Access Devices, managed by the BroadWorks platform. In a non-geographically-redundancy network, the devices use SIP to register to a single SIP SBC IP address. To support geographic redundancy of SBCs, the devices must support registration to multiple IP addresses. It must select the proper IP address in...


See only a Sampling of RTP frames in a Wireshark Packet Capture

Question: How do you make a display filter that filters out most RTP frames, but leaves a representative sample? Sometimes it's convenient to see a sampling of RTP frames in Wireshark, without having to see 50 per second. Answer: Rather then see 50 frames per second for every RTP flow, how about one frame every 5 seconds? Wireshark display filter: rtp[3:1]==0 or rtp.marker==1 Shows an RTP pa...


RTP Troubleshooting Tip: See a Sample of RTP frames in a Packet Capture

Question: How do you make a display filter that filters out most RTP frames, but leaves a representative sample? Sometimes it's convenient to see a sampling of RTP frames in Wireshark, without having to see 50 per second. Answer: Rather then see 50 frames per second for every RTP flow, how about one frame every 5 seconds? Wireshark display filter: rtp[3:1]==0 or rtp.marker==1...


SIP Trunking: Public, Private, VPN, and Why

When you're connecting to the rest of the world to make and receive phone calls, you have several design options available. Or, more precisely, your Voice Service Providers have many options available. VoIP via Layer-3 VPN In this case, a Layer-3 VPN, such as MPLS over the Voice Provider’s own equipment, is used to connect a Voice customer to the Voice service provider. Shared infrastructure i...


BroadSoft BroadWorks Database Server (DBS) - Cheat Sheet

The BroadSoft BroadWorks DBS is a different animal than other BroadWorks servers, and it requires a special set of commands to keep it alive and well. The level of care and feeding required for the database reminds of BroadWorks App Server release R12 and R13; those were not happy days. Check status of the FRA Disk Group dbsctl diskinfo /etc/init.d/oracleasm listdisks On a healthy, normal sys...


Net Neutrality: Nobody Wants an ISP To Mangle Their Data

"Network Neutrality" advocates teach us that banning certain Active Queue Management (AQM) algorithms will result in greater freedom on the Internet. For example: Barack Obama wants to ban "Paid Prioritization," which Cisco calls "Low Latency Queueing". Even folks interested in computers, but who don't build or run networks, seem to have some downright strange opinions. For example, when Netfli...


Cisco Crowdsources Critical Announcements: SSL Certificate Changes on SPA-500 phones

The Cisco Small Business SPA-500 series phones (such as the SPA-502G, SPA-508G) include a Cisco-signed SSL certificate. Until very recently, all of the Cisco SPA-500-series phones shipped were signed by a Sipura certificate. Sipura was the Korean company that was bought by Linksys before Linksys was bought by Cisco. Sometime after August 2013, Cisco Small Business started shipping phones signed...


152 Test Criteria for SIP Phones, ATAs, and other Telephony Endpoints

When it comes to telephones, everybody has certain expectations. Nobody wants a phone that fails occasionally. And most service providers have a model of phone that they trust; nobody wants to try out a new SIP phone and learn that it fails in an obscure, but important feature. For example: Have you seen the new Yealinks? Or what about the improved Grandstreams?   How do you ensure the phone is...


"URL" Dialing: Calling arbitrary SIP places on the Internet

BroadWorks calls it "URL Dialing": calling from your hosted PBX VoIP phone or SIP Trunking device to a random SIP URI. Lately, Polycom has been handing out SIP URIs and inviting people to test out their video bridges. Let's say you want to call to sip:1234@opensips.org -- how should it work? Most VoIP services providers -- such as those built on BroadWorks and Metaswitch -- don't allow calls fr...


High Performance SIP Trunking / Termination Service using Metaswitch and Oracle/Acme Packet

    Metaswitch and Oracle Communications (formerly Acme Packet) would love to own each other's customers; and many service providers own both. This design shows how the two can be combined to make a scalable, high-performance SIP termination platform appropriate for outbound call centers. High-performance call termination can be a challenge; many conventional systems, rich in SIP trunking feat...


Quality: Required. QoS: Never. (Quality VoIP Across the Public Internet.)

1. Introduction Customers want quality voice and video. This can be readily provided using engineered links -- i.e., paths that prioritize, reserve, or otherwise guarantee that the real-time voice and video packets will be delivered within the required timing constraints. But because of the wonderful cost reductions of Internet bandwidth, customers would prefer to get the quality voice and vide...


Grass Is Greener In The Other Market: Metaswitch and Broadsoft

Two of my favorite companies, BroadSoft and Metaswitch, are showing that they're interested in the other guy's turf. At the recent Metaswitch Forum in New Orleans, the talk was about the "NFV" standard for managing telecom software, and about Business Services. Metaswitch's customer base -- independent telcos -- has long been strong in TDM voice (PRI, CAS T1) residential (analog service via GR-...