Telecom For Dummies

International calls are prone to having quality and completion issues. You might have to wait 45 seconds before you hear the phone ring on the far end. When someone picks up the call, you might hear static, echo, or low volume on the call, making it difficult to hear what the other person is saying. You can still have a conversation, but it becomes a bit more challenging than you might want. It’s not fun.

If a fax machine experiences any of these issues, the fax will probably fail. Any issue that prevents the clean transmission of data in a timely manner typically kills a fax transmission.

There are four main reasons international faxes fail, and unfortunately, there isn’t a lot you can do to change them. They are:

• Antiquated network in the destination country: If you are trying to fax to a company in rural China or a small village in Africa, for example, the network might be old, outdated, and inherently prone to dropping calls. The company might be maxing out its bandwidth, and without enough bandwidth to allow the fax machines to synch up after the call connects, your fax will fail. Solution: Make multiple attempts at a lower baud rate in order to complete your fax.

• Receiving fax can’t increase baud rate fast enough: If your fax is transmitting at 64 kbps, and the receiving fax is 20 years old and has a maximum throughput of 1200 baud, there might not been enough time for your fax machine to slow down and the remote fax to speed up before your fax machine loses synch and drops the call. Solution: Your best bet is to lower the speed of your fax machine and keep trying the call. Eventually, it should complete.

• Fax machines time out before connection: Every fax machine has a timer on it that disconnects a call if it’s not answered. The factory default on this timer is about 30 seconds, and for domestic calls, that is acceptable. The problem is that international calls take more time to set up. There can be a 30- to 45-second PDD on an international call. If the fax machine you are dialing to picks up on the second ring, it might be a full minute before your fax machine receives a connection. Solution: The easiest fix is to simply set the wait for connect timer on your fax machine to 2 minutes, or at least to 90 seconds.

• Carrier compression techniques on international calls: Some underlying carriers work so hard to maximize their profits that they squeeze every call going over their network to tenuous levels. This isn’t much of a problem on voice calls, but fax machines need enough bandwidth to allow them to synch up after the call connects. If there is too much latency on the call, the fax machines won’t synch up and the call will fail. Solution: There might be nothing you can do to resolve this problem, except to open up trouble tickets and push your carrier to move the traffic to another underlying carrier.