One of the essential components in any VoIP system is the Internet connection. Without a reliable Internet connection, VoIP can quickly become a frustrating experience. Crucial to a reliable connection is the router. This often-overlooked component is the one thing keeping us all online.
When it comes to routers and VoIP you tend to get what you pay for. Cheaper routers will need rebooting at regular intervals to maintain a connection and can often prevent multiple phones from connecting to a VoIP service. In an ideal world we’d be able to buy brand new routers for every VoIP site. This isn’t an ideal world and you’ll often find yourself trying to make the best of a bad router.
Diagnosing A Connection Problem
The first thing to look at when diagnosing a connection problem is whether the router has “SIP ALG”. This stands for “SIP Application Level Gateway”. This is a piece of technology that is designed to help VoIP connections but is redundant when using VIP VoIP. In fact it is usually very buggy and can cause many head aches. If you are having problems with the following; then potentially you need to disable SIP ALG on the router:
- Intermittent connectivity
- Only being able to get a few phones online at a site.
On some routers this can disabled from the web interface for the router. On others this is done using a command line tool. Some troublesome router models include:
- BT Home routers – These tend to be very problematic and should be avoided if possible.
- Sky, Virgin and TalkTalk home routers – These also tend to be problematic and should be avoided if possible.
- TP Link routers – These tend to have problems after a few months of uptime and need rebooting on a regular basis.
- Thompson routers – These need SIP ALG disabling and this can be tricky as it requires a command line tool.
- Netgear DGN1000 – This has a faulty firmware and SIP ALG can not be disabled on this router. Although it can be worked around using the information below.
VIP VoIP recommends Draytek routers. They are very reliable and have settings for prioritizing VoIP traffic.
Disabling SIP ALG – Step By Step Instructions
Further Problems & Solutions
If after disabling SIP ALG you are still experiencing problems the next thing to look at is ports. Some routers and some ISPs will interfere with the ports that enable VoIP to work. To get around this, we at VIP VoIP provide individual ports for all our servers that bypass most routers and ISPs. The individual port number for your server is available through our reseller portal, or you can contact us and we’ll provide the information to you. Once you have the port number for your server you can enter that in to the phones that are having problems.
If there are still connection problems then we can look at changing the technology the phones use to connect. By default most phones use UDP to talk to our servers. Sometimes changing the technology to TCP will get around troublesome routers. VIP VoIP also offer full encryption of VoIP traffic using TLS which often overcomes router issues.
If you continue to have problems then you should contact your ISP and see if they can give you information on the quality of connection. Some ISPs even have information on whether the connection went down at any point. This could coincide with your VoIP problems. Connections going down regularly can be a sign of bad cabling or an ISP having equipment.
Top Tip
Also it is worth checking if other people are abusing the Internet connection while people are trying to make calls. Check that people in the office aren’t downloading large files or updates while the VoIP phones are in use. If possible put the phones a separate broadband connection to avoid those sorts of problems entirely.