Numbers are a key concept to understand when working with the Routee Voice API. The following points should be considered before starting to consume Voice Api.
Within the Routee Voice API all numbers are in E.164 format. This means that numbers:
Omit both a leading + and the international access code such as 001.
Contain no special characters, such as a space, () or -
For example, a US number would have the format 14155550101. A UK number would have the format 447700900123.

Outgoing SenderId

When making an outbound call from Routee Voice API, we can specify a SenderID. SenderID can either be a valid Phone Number or an alphanumeric. Note that Alphanumeric SenderID is not supported by all providers and may result in outgoing SenderId to be represented as Unknown.

Incoming SenderId

Routee endeavors to present to you the caller ID of the party calling your Routee number in international format. However, this can occasionally be incorrectly formatted by the originating network. Routee passes through the number received from the number supplier.
Incoming Call Numbers
Routee offers for rent incoming numbers located in many countries around the world. In some countries, the numbers may be enabled for SMS or Voice only, or in others, they will support both.
To use a number you have rented from Routee, you need to link that number to a Dialplan URL. In case of an Inbound call to a Number, at Dialplan Url you 'll be able to see the originator of call at from variable and the Virtual Number at to variable.