They do have calling cards available for sale everywhere to be used in the local call boxes, which are usually two different types. Directions may not always be in English. However, the ISP's are not as reliable and it is sometimes difficult to get on particularly in the evening, and it's not unusual to get booted off. Cellphones are everywhere in Egypt, it has one of the highest usages for cellphones in the world, which makes sense as their Telephone system can't keep up with the regular phone requirements. They have international cellphone service, and it covers just about everywhere, even the most remote areas.
Outgoing calls are quite expensive, but in most cases there is no charge for incoming calls.
If renting independently, check all the charges ahead of time. They will of course pay for an international call, but it will be at your home rates. This service is NOT set up for outbound calls. It is ideal for those at home to call you in case of emergencies, or just to keep you up to date with things at home.