You should ask your travel agent whether or not the hotel you are staying in has a digital system with data ports on the telephones and the configuration of these ports in case you need to take a telephone adapter. DO NOT hardwire a direct connection in a digital system. This could permanently damage your modem and even shut down the hotel's telephone system. Hardwiring a connection from the wall in an analog system is more reliable. You should use a line tester to make sure that a connection has been established before using your modem.
Line noise is a problem that can occur in less modernized countries.
In most cases, you are at the mercy of the telephone exchange but there are a few tricks that might help reduce the interference. First, try connecting at lower modem speeds. If you usually work at 14,400 bds., try reducing to 9,600 bds. Or, you can try working very late at night when there are fewer people using the network. There is also a type of deliberately created line noise called tax impulsing.