A server for routing a plurality of encoded portions of a video over a network between a transmitting device and a plurality of receiving devices, the server comprising one or more server units being configured to: receive a respective error message over a feedback channel from at least two respective ones of the plurality of receiving devices, each respective error message including lost portion data indicating at least one of said plurality of encoded portions that has not been both received and decoded at the respective one of said plurality of receiving devices, and source portion data indicating a respective source portion, the source portion being one of said encoded portions successfully received and not rejected as corrupt, which was decoded or is known to be decodable at the respective one of said plurality of receiving devices; based on the received error messages, generate a collective error message for use by the transmitting device to generate a recovery portion; and obtain, from the transmitting device, the recovery portion based on the collective error message, wherein said collective error message includes an indication of a collective target portion being one of said plurality of encoded portions determined based on the lost portion data included in each respective one of the error messages, and a collective source portion determined based on the source portion data included in each one of the respective error messages,, wherein said collective source portion is determined as a least recent one of the indicated source portions, or is one of said plurality of encoded portions being less recent than said least recent one of the indicated source portions, and wherein said recovery portion is based on the collective error message in that the recovery portion comprises the collective target portion inter-encoded relative to the collective source portion. receive a respective error message over a feedback channel from at least two respective ones of the plurality of receiving devices, each respective error message including lost portion data indicating at least one of said plurality of encoded portions that has not been both received and decoded at the respective one of said plurality of receiving devices, and source portion data indicating a respective source portion, the source portion being one of said encoded portions successfully received and not rejected as corrupt, which was decoded or is known to be decodable at the respective one of said plurality of receiving devices; based on the received error messages, generate a collective error message for use by the transmitting device to generate a recovery portion; and obtain, from the transmitting device, the recovery portion based on the collective error message, wherein said collective error message includes an indication of a collective target portion being one of said plurality of encoded portions determined based on the lost portion data included in each respective one of the error messages, and a collective source portion determined based on the source portion data included in each one of the respective error messages,, wherein said collective source portion is determined as a least recent one of the indicated source portions, or is one of said plurality of encoded portions being less recent than said least recent one of the indicated source portions, and wherein said recovery portion is based on the collective error message in that the recovery portion comprises the collective target portion inter-encoded relative to the collective source portion.