Isolated and flexible network data transmission between computing infrastructure collections

A method, comprising:

• performing, by one or more computing devices of a data transport service of a provider network:
• assigning respective channels for use by respective users, wherein a respective source, destination, and capacity to transmit data are associated with individual ones of the respective channels, and wherein the respective source is within a first computing infrastructure collection of the provider network and the respective destination is within a second computing infrastructure collection of the provider network;
• and
• for a particular channel of the respective channels, based on the capacity associated with the particular channel:
• reserving, for the particular channel, network resource capacity to transmit the data between the first and second computing infrastructure collections, wherein the reserved network resource capacity is at least a portion of a total amount of network resource capacity available to the data transport service to transmit data between the first and second computing infrastructure collections;
• reserving, for the particular channel, compute instance capacity to send the data to the specified destination using the reserved network resource capacity, wherein the reserved compute instance capacity is at least a portion of a total compute instance capacity available to the data transport service for sending data from the first computing infrastructure collection to the second computing infrastructure collection or other computing infrastructure collections;
• wherein the reserved network resource capacity and reserved compute instance capacity are dedicated to the particular channel;
• and
• sending the data from the first computing infrastructure collection to the second computing infrastructure collection using the particular channel.

One or more non-transitory computer-accessible storage media storing program instructions that when executed on or across one or more processors:

• assign respective channels for use by respective users of a data transport service of a provider network, wherein a respective source, destination, and capacity to transmit data are associated with individual ones of the respective channels, and wherein the respective source is within a first computing infrastructure collection of the provider network and the respective destination is within a second computing infrastructure collection of the provider network;
• for a particular channel of the respective channels, based on the capacity associated with the particular channel:
• reserve, for the particular channel, network resource capacity to transmit the data between the first and second computing infrastructure collections, wherein the reserved network resource capacity is at least a portion of a total amount of network resource capacity available to the data transport service to transmit data between the first and second computing infrastructure collections;
• reserve, for the particular channel, compute instance capacity to send the data to the specified destination using the reserved network resource capacity;
• and
• wherein the reserved network resource capacity and reserved compute instance capacity are dedicated to the particular channel;
• receive a message comprising an identifier for a portion of data to be replicated from a source within the first computing infrastructure collection to a destination within the second computing infrastructure collection;
• in response to a determination that the portion of data is to be replicated using the particular channel, forward the message to an admission queue for the particular channel;
• and
• send the portion of data from the first computing infrastructure collection to the second computing infrastructure collection using the particular channel.