Audio communication may be established between a plurality of communication units in a communication system that includes a dispatch switching center in the following manner. A first communication unit generates information to be distributed to a second communication unit. The dispatch switching center receives a digital packet including the information to be distributed, and ascertains an identifier associated with the second communication unit. The dispatch switching center replicates the information to be distributed, and uses the identifier to distribute the replicated information to the second communication unit.

A seat post assembly attaching a seat to a bicycle is provided. The assembly includes an elastomeric shock absorbing subassembly bonded to a curved bar which is received in a tube of the bicycle at one end and attaches to a seat at the other. The subassembly is also retained on the inside of the tube.

A network protocol, transmission format, and hardware interface facilitating high speed transmission of raster data from a host computer having a raster image processor to a printer. The protocol and hardware interface of the present invention minimize memory-to-memory transfers of raster data by defining data transfers directly from local memory of network hardware to memory associated with a raster connection management module. The transmission format of the present invention minimizes handshaking by sending a large number of data packets between acknowledgements. In addition, the present invention allows a host computer system to request printer profile information, and process raster data based on the profile information.

A system for printing a document over a network including a network, a printer and a raster image processor. The network connects at least three computing resources. The printer is coupled to the network and included in the computing resources. The printer includes a printer network connection, a printer virtual connection mechanism and a mechanism for printing the document based on the raster image. The printer network connection transfers data packets to and from the computing resources. The printer virtual connection mechanism receives a raster image representative of a document from a member of the plurality of computer resources to which a unique virtual connection has been established. The raster image processor is coupled to the network and included in the computing resources. The raster image processor includes raster image processor network connection mechanism, a rendering, mechanism, and a raster image processor virtual connection mechanism. The raster image processor network connection mechanism transfers information to and from the computing resources. The mechanism rendering mechanism renders a series of page description language instructions representative of the document into the raster image. The raster image processor virtual connection mechanism transmits a raster image to a printer via the unique virtual connection. The virtual connection maintenance mechanism opens, maintains, and closes unique virtual connections between printer and raster image processor.

A network protocol facilitates high speed transmission of raster data from a server to a client. The protocol defines a first sub-protocol for negotiating a connection and preparing to transmit a print job, and a second sub-protocol for transmitting a large quantity of raster data. The second sub-protocol allows the recipient of the data to dictate the order in which various types of data are transmitted, while allowing for efficient error correction of lost and/or corrupted packets. In one embodiment, a server is configured to transmit data to a client using the protocol of the present invention. In another embodiment, a client is configured to receive data from the server according to the protocol of the present invention. The protocol minimizes handshaking by sending a large number of data packets between acknowledgements.