| VoIP is revolutionizing communication for both | | | | Unfortunately, if you suspect poor service from your |
| residential and commercial use. Although the residential | | | | ISP, you need to test a different ISP, get a |
| demand for VoIP has been strong for years, small | | | | professional's help or make use of a diagnostic tool. I |
| businesses are exchanging their antiquated digital | | | | discuss a tool that you can use to inspect your ISPs |
| phone systems with VoIP provider services. These | | | | network and pinpoint the exact location of a problem |
| services are marketed under the names Hosted PBX, | | | | at the end of this article in my bio. |
| Hosted VoIP, IP PBX, Virtual PBX and many more. | | | | 3. Hubs and Ethernet Switches.. Ethernet switches and |
| Adoption of these services continues on a frenetic | | | | hubs are the boxes that all of your data cabling |
| pace despite the myriad of deployment problems | | | | connects to tie your computer devices together. Your |
| when utilizing VoIP over the Internet. | | | | LAN cannot contain any hubs. Instead Ethernet |
| Deployment problems manifest themselves with quality | | | | switches must be used, 100BaseT minimum. |
| of voice issues. Technical articles which offer advice | | | | 4. Multiple Chained Ethernet Switches. Homes and |
| on solving VoIP voice quality problems discuss jitter, | | | | offices with older wiring may use multiple Ethernet |
| latency and MOS scores. You do not have to become | | | | switches at desks, rooms and blocks of cubes to |
| a VoIP nerd to make a phone call. This article shares | | | | share single wiring drops back to the main LAN |
| the most common deployment issues that cause jitter, | | | | Ethernet switch. Passing VoIP through multiple Ethernet |
| latency and poor MOS scores without ever discussing | | | | switches to reach the Internet can cause problems. |
| them. | | | | Find ways to eliminate these extra devices through |
| Symptoms of mild voice quality problems consist of | | | | wireless access points and additional cabling. |
| robotic, distorted or slightly choppy voice. In most | | | | 5. Insufficient Bandwidth for Number of VoIP Calls. |
| cases, all the words can still be understood. Moderate | | | | Without going into the dirty details of voice |
| problems are occasional broken words which have to | | | | compression and codecs, you should in general have |
| be repeated. Severe problems include frequently | | | | about 60kbps of upload bandwidth for every |
| distorted and choppy voice, lost sentences and | | | | simultaneous voice call. Insufficient bandwidth will choke |
| dropped phone calls. If you are experiencing any of the | | | | your voice packets. |
| problems, here is a short list of common causes: | | | | 6. Poor Wiring Inside Building before Cable or DSL |
| 1. Voice Prioritization. Most Internet connections are | | | | Modem. For DSL, each building or home has a |
| though DSL or Cable. These connections typically | | | | DMARC (characterized by a wire block with orange |
| offer more bandwidth from the Internet (download) | | | | cover) or Network Interface Box (homes). The line |
| than to it (upload). Because the upload speed is smaller, | | | | carrying the DSL circuit should go straight from the |
| voice packets usually need to be prioritized going out | | | | DMARC to DSL filter and then DSL modem. No other |
| to the Internet. If you can hear the outside caller just | | | | devices or connections should be in between. Cable |
| fine but they have trouble hearing you, than this may | | | | modems must work off of the primary splitter (not go |
| be the problem. | | | | through multiple splitters) and should be the leg with the |
| Voice prioritization MUST be enforced between the | | | | highest decibel level. When your cable repairman visits, |
| cable or DSL modem and your LAN. More and more | | | | he can verify. |
| routers include this ability and it is becoming easier for | | | | 7. Other Applications May Prioritize Their Packets. Any |
| the average user to set-up, however, a VoIP | | | | application can choose to use prioritization flags in their |
| professional may still be needed. | | | | packets. These applications may be in use with or |
| Any use of a DSL or cable modem integrated WiFi | | | | without the network administrator's knowledge including |
| access point is likely bypassing your voice prioritization. | | | | video and the myriad of consumer voice services |
| Further, you may experience Internet problems just by | | | | such as Skype, Vonage, IMs, etc. Assuming the use of |
| having your WiFi radio active in your modem when | | | | these services is approved, your voice prioritization |
| using your microwave or cordless telephone. It is | | | | programming and Internet bandwidth needs to account |
| strongly recommended that you disable this feature in | | | | for the extra bandwidth consumption. |
| modems and use a separate WiFi access point | | | | These are 7 of the most common problems that may |
| whose traffic must pass through voice prioritization to | | | | cause jitter, latency, poor MOS scores or just bad |
| get to the Internet. | | | | voice quality. In some instances, you will need |
| 2. Poor Service from Internet Service Provider (ISP). | | | | professionals to help with proper programming and |
| VoIP is very sensitive to problems in the Internet and | | | | problem detection. Many tools exist as well. If you |
| many ISPs do not take care that they provide a | | | | believe all inside your house or building is in good shape, |
| reliable circuit. ISP networks are comprised of many | | | | determining whether the problem is caused by your |
| routers frequently called hops. Each hop has a | | | | ISP can be difficult. |
| potential for network congestion which may be fine for | | | | My website will make available a tool to check out |
| normal data traffic but will cause problems for VoIP. | | | | your Internet connection in August of 2010. Subscribe |
| Other causes of poor ISP service are faulty DSL or | | | | to my blog to be alerted of our new tool's availability |
| cable modem, old outside cabling that has become | | | | as it will deliver important knowledge and statistics |
| susceptible to weather and router problems within ISP | | | | when diagnosing Internet problems or dealing with your |
| network. Further, DSL service may be degraded by | | | | ISP. It is free to use and nothing like it exists on the |
| frequency interference in the providers cable bundle, | | | | Internet today. |
| load coils and bridge taps. | | | | |