NFS Version 4 is the IETF standard for file sharing. To maintain NFS Version 4's utility and currency, the working group is chartered to (1) maintain the existing NFSv4, NFSv4.1 and related specifications, such as RPC and XDR, (2) progress these specifications along the standards track, (3) develop a protocol to create a federated namespace using NFSv4's existing referral mechanisms. (1) NFS version 4.0 maintenance Under this charter item, the WG correct errors and ambiguities in the protocol currently specified in RFC 3530 and advances it along the standards track. Extensions of any other kind are out of scope under this charter item. (2) NFS Version 4.1 Maintenance As with NFSv4.0, the WG will address errors or ambiguities in the NFSv4.1 protocol and related specifications in support of progressing implementations. (3) RPC and XDR protocol maintenance The NFSv4 protocol depends on two related specifications: ONC RPC and XDR. Similar to charter item (1), the WG may correct errors and ambiguities in the ONC RPC and XDR protocols currently specified by RFCs 1831, 1833 and 2203. In conjunction with the advancement of the NFSv4 specification along the standards track, the WG will also work on the advancements of its ONC RPC and XDR dependencies. The WG will also update the ONC RPC specification for compatibility with IPv6. Additionally, it will create an IANA registry for RPC program numbers and seed it with a registry Sun has been maintaining. (4) Federated Namespace The NFSv4 protocol provides a referral mechanism that allows a server to redirect a client to another server. The working group will produce documents describing a mechanism for creating a federated namespace (single global name space for a set of NFSv4 servers) using the NFSv4 protocol's referral capabilities. The file system federation protocol will enable file access and namespace traversal across collections of independently administered fileservers. No modifications will be made to the NFS client to server protocol.