--- 1/draft-ietf-dmm-ondemand-mobility-13.txt 2018-03-19 08:13:34.144972325 -0700 +++ 2/draft-ietf-dmm-ondemand-mobility-14.txt 2018-03-19 08:13:34.264975165 -0700 @@ -1,25 +1,25 @@ DMM Working Group A. Yegin Internet-Draft Actility Intended status: Informational D. Moses -Expires: July 28, 2018 Intel +Expires: September 20, 2018 Intel K. Kweon J. Lee J. Park Samsung S. Jeon Sungkyunkwan University - January 24, 2018 + March 19, 2018 On Demand Mobility Management - draft-ietf-dmm-ondemand-mobility-13 + draft-ietf-dmm-ondemand-mobility-14 Abstract Applications differ with respect to whether they need IP session continuity and/or IP address reachability. The network providing the same type of service to any mobile host and any application running on the host yields inefficiencies. This document describes a solution for taking the application needs into account by selectively providing IP session continuity and IP address reachability on a per- socket basis. @@ -32,21 +32,21 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on July 28, 2018. + This Internet-Draft will expire on September 20, 2018. Copyright Notice Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -122,44 +122,44 @@ Applications performing brief communication (e.g., ping) can survive without having IP session continuity support. Achieving IP session continuity and IP address reachability with Mobile IP incurs some cost. Mobile IP protocol forces the mobile host's IP traffic to traverse a centrally-located router (Home Agent, HA), which incurs additional transmission latency and use of additional network resources, adds to the network CAPEX and OPEX, and decreases the reliability of the network due to the introduction of a single point of failure [RFC7333]. Therefore, IP session continuity - and IP address reachability should be provided only when necessary. + and IP address reachability SHOULD be provided only when necessary. Furthermore, when an application needs session continuity, it may be able to satisfy that need by using a solution above the IP layer, such as MPTCP [RFC6824], SIP mobility [RFC3261], or an application- layer mobility solution. These higher-layer solutions are not subject to the same issues that arise with the use of Mobile IP since they can utilize the most direct data path between the end-points. But, if Mobile IP is being applied to the mobile host, the higher- layer protocols are rendered useless because their operation is inhibited by Mobile IP. Since Mobile IP ensures that the IP address of the mobile host remains fixed (despite the location and movement of the mobile host), the higher-layer protocols never detect the IP- layer change and never engage in mobility management. This document proposes a solution for applications running on mobile hosts to indicate whether they need IP session continuity or IP address reachability. The network protocol stack on the mobile host, - in conjunction with the network infrastructure, would provide the - required type of IP service. It is for the benefit of both the users - and the network operators not to engage an extra level of service - unless it is absolutely necessary. It is expected that applications - and networks compliant with this specification would utilize this - solution to use network resources more efficiently. + in conjunction with the network infrastructure, provides the required + type of IP service. It is for the benefit of both the users and the + network operators not to engage an extra level of service unless it + is absolutely necessary. It is expected that applications and + networks compliant with this specification will utilize this solution + to use network resources more efficiently. 2. Notational Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 3. Solution 3.1. Types of IP Addresses @@ -242,26 +242,26 @@ 3.3. On Demand Nature At any point in time, a mobile host may have a combination of IP addresses configured. Zero or more Non-persistent, zero or more Session-lasting, zero or more Fixed and zero or more Graceful- Replacement IP addresses may be configured by the IP stack of the host. The combination may be as a result of the host policy, application demand, or a mix of the two. When an application requires a specific type of IP address and such - an address is not already configured on the host, the IP stack shall + an address is not already configured on the host, the IP stack SHALL attempt to configure one. For example, a host may not always have a Session-lasting IP address available. When an application requests - one, the IP stack shall make an attempt to configure one by issuing a + one, the IP stack SHALL make an attempt to configure one by issuing a request to the network (see Section 3.4 below for more details). If - the operation fails, the IP stack shall fail the associated socket + the operation fails, the IP stack SHALL fail the associated socket request and return an error. If successful, a Session-lasting IP Address gets configured on the mobile host. If another socket requests a Session-lasting IP address at a later time, the same IP address may be served to that socket as well. When the last socket using the same configured IP address is closed, the IP address may be released or kept for future applications that may be launched and require a Session-lasting IP address. In some cases it might be preferable for the mobile host to request a new Session-lasting IP address for a new opening of an IP session @@ -312,21 +312,21 @@ An application that wishes to secure a desired service will call getsc() with the service type definition and a place to contain the provided IP address, and call bind() to associate that IP address with the Socket (See pseudo-code example in Section 4 below). When the IP stack is required to use a source IP address of a specified type, it can use an existing address, or request a new IP prefix (of the same type) from the network and create a new one. If the host does not already have an IPv6 prefix of that specific type, - it must request one from the network. + it MUST request one from the network. Using an existing address from an existing prefix is faster but might yield a less optimal route (if a hand-off event occurred after its configuration). On the other hand, acquiring a new IP prefix from the network may be slower due to signaling exchange with the network. Applications can control the stack's operation by setting a new flag - ON_NET flag - which directs the IP stack whether to use a preconfigured source IP address (if exists) or to request a new IPv6 prefix from the current serving network and configure a new IP @@ -342,146 +342,147 @@ (TCP) with a Session-Lasting source IP address: #include #include // Socket information int s ; // Socket id // Source information (for secsc() and bind()) sockaddr_in6 sourceInfo // my address and port for bind() -in6_addr sourceAddress // will contain the provisioned source - // IP address + in6_addr sourceAddress // will contain the provisioned + // source IP address uint8_t sc_type = IPV6_REQUIRE_SESSION_LASTING_IP ; // For requesting a Session-Lasting // source IP address // Destination information (for connect()) sockaddr_in6 serverInfo ; // server info for connect() // Create an IPv6 TCP socket s = socket(AF_INET6, SOCK_STREAM, 0) ; if (s!=0) { // Handle socket creation error // ... } // if socket creation failed else { // Socket creation is successful - // The application cannot connect yet, since it wants to use a - // Session-Lasting source IP address It needs to request the - // Session-Lasting source IP before connecting + // The application cannot connect yet, since it wants to use + // a Session-Lasting source IP address It needs to request + // the Session-Lasting source IP before connecting if (setsc(s, &sourceAddress, &sc_type)) == 0){ - // setting session continuity to Session Lasting is successful - // sourceAddress now contains the Session-Lasting source IP - // address + // setting session continuity to Session Lasting is + // Successful. sourceAddress now contains the Session- + // LAsting source IP address // Bind to that source IP address sourceInfo.sin6_family = AF_INET6 ; sourceInfo.sin6_port = 0 // let the stack choose the port sourceInfo.sin6_address = sourceAddress ; // Use the source address that was // generated by the setsc() call if (bind(s, &sourceInfo, sizeof(sourceInfo))==0){ // Set the desired server's information for connect() serverInfo.sin6_family = AF_INET6 ; serverInfo.sin6_port = SERVER_PORT_NUM ; serverAddress.sin6_addr = SERVER_IPV6_ADDRESS ; // Connect to the server if (connect(s, &serverInfo, sizeof(serverInfo))==0) { - // connect successful (3-way handshake has been completed - // with Session-Lasting source address. + // connect successful (3-way handshake has been + // completed with Session-Lasting source address. // Continue application functionality // ... } // if connect() is successful else { // connect failed // ... - // Application code that handles connect failure and closes - // the socket + // Application code that handles connect failure and + // closes the socket // ... } // if connect() failed } // if bind() successful else { // bind() failed // ... - // Application code that handles bind failure and closes - // the socket + // Application code that handles bind failure and + // closes the socket // ... } // if bind() failed - } // if setsc() was successful and of a Session-Lasting source address was provided + } // if setsc() was successful and of a Session-Lasting + // source IP address was provided else { - // application code that does not use Session-lasting IP address - // The application may either connect without the desired - // Session-lasting service, or close the socket - //... + // application code that does not use Session-lasting IP + // address. The application may either connect without + // the desired Session-lasting service, or close the + // socket... } // if setsc() failed } // if socket was created successfully // The rest of the application's code // ... 5. Backwards Compatibility Considerations - Backwards compatibility support is required by the following 3 types + Backwards compatibility support is REQUIRED by the following 3 types of entities: - The Applications on the mobile host - The IP stack in the mobile host - The network infrastructure 5.1. Applications Legacy applications that do not support the OnDemand functionality will use the legacy API and will not be able to take advantage of the On-Demand Mobility feature. - Applications using the new OnDemand functionality must be aware that + Applications using the new OnDemand functionality MUST be aware that they may be executed in legacy environments that do not support it. Such environments may include a legacy IP stack on the mobile host, legacy network infrastructure, or both. In either case, the API will return an error code and the invoking applications may just give up and use legacy calls. 5.2. IP Stack in the Mobile Host - New IP stacks must continue to support all legacy operations. If an - application does not use On-Demand functionality, the IP stack must + New IP stacks MUST continue to support all legacy operations. If an + application does not use On-Demand functionality, the IP stack MUST respond in a legacy manner. If the network infrastructure supports On-Demand functionality, the - IP stack should follow the application request: If the application - requests a specific address type, the stack should forward this + IP stack SHOULD follow the application request: If the application + requests a specific address type, the stack SHOULD forward this request to the network. If the application does not request an - address type, the IP stack must not request an address type and leave + address type, the IP stack MUST NOT request an address type and leave it to the network's default behavior to choose the type of the allocated IP prefix. If an IP prefix was already allocated to the host, the IP stack uses it and may not request a new one from the network. 5.3. Network Infrastructure The network infrastructure may or may not support the On-Demand functionality. How the IP stack on the host and the network infrastructure behave in case of a compatibility issue is outside the scope of this API specification. 5.4. Merging this work with RFC5014 [RFC5014] defines new flags that may be used with setsockopt() to influence source IP address selection for a socket. The list of flags include: source home address, care-of address, temporary address, public address CGA (Cryptographically Created Address) and non-CGA. When applications require session continuity service and - use setsc() and bind(), they should not set the flags specified in + use setsc() and bind(), they SHOULD NOT set the flags specified in [RFC5014]. However, if an application sets a specific option using setsockopt() with one of the flags specified in [RFC5014] and also selects a source IP address using setsc() and bind() the IP address that was generated by setsc() and bound using bind() will be the one used by traffic generated using that socket and options set by setsockopt() will be ignored. If bind() was not invoked after setsc() by the application, the IP @@ -492,47 +493,49 @@ 6. Summary of New Definitions 6.1. New APIs setsc() enables applications to request a specific type of source IP address in terms of session continuity. Its definition is: int setsc (int sockfd, in6_addr *sourceAddress, sc_type addressType) ; Where: - - sockfd - is the socket descriptor of the socket with which a - specific address type is associated - - sourceAddress - is a pointer to an area allocated for setsc() to place - the generated source IP address of the desired session - continuity type + - sockfd - is the socket descriptor of the socket with which + a specific address type is associated + - sourceAddress - is a pointer to an area allocated for setsc() to + place the generated source IP address of the + desired session continuity type - addressType - Is the desired type of session continuity service. - It is a 3-bit field containing one of the following - values: + It is a 3-bit field containing one of the + following values: 0 - Reserved 1 - FIXED_IPV6_ADDRESS 2 - SESSION_LASTING_IPV6_ADDRESS 3 - NON_PERSISTENT_IPV6_ADDRESS 4 - GRACEFUL_REPLACEMENT_IPV6_ADDRESS 5-7 - Reserved setsc() returns the status of the operation: - 0 - Address was successfully generated - - EAI_REQUIREDIPNOTSUPPORTED - the required service type is not supported - - EAI_REQUIREDIPFAILED - the network could not fulfill the desired request + - EAI_REQUIREDIPNOTSUPPORTED - the required service type is not + supported + - EAI_REQUIREDIPFAILED - the network could not fulfill the desired + request - setsc() may block the invoking thread if it triggers the TCP/IP stack + setsc() MAY block the invoking thread if it triggers the TCP/IP stack to request a new IP prefix from the network to construct the desired source IP address. If an IP prefix with the desired session continuity features already exists (was previously allocated to the mobile host) and the stack is not required to request a new one as a result of setting the IPV6_REQUIRE_SRC_ON_NET flag (defined below), - setsc() may return immediately with the constructed IP address and + setsc() MAY return immediately with the constructed IP address and will not block the thread. 6.2. New Flags The following flag is added to the list of flags in the IPV6_ADDR_PREFERENCE option at the IPPROTO6 level: IPV6_REQUIRE_SRC_ON_NET - set IP stack address allocation behavior If set, the IP stack will request a new IPv6 prefix of the desired @@ -584,25 +587,20 @@ [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5014] Nordmark, E., Chakrabarti, S., and J. Laganier, "IPv6 Socket API for Source Address Selection", RFC 5014, DOI 10.17487/RFC5014, September 2007, . - [RFC6724] Thaler, D., Ed., Draves, R., Matsumoto, A., and T. Chown, - "Default Address Selection for Internet Protocol Version 6 - (IPv6)", RFC 6724, DOI 10.17487/RFC6724, September 2012, - . - 11.2. Informative References [I-D.sijeon-dmm-use-cases-api-source] Jeon, S., Figueiredo, S., Kim, Y., and J. Kaippallimalil, "Use Cases and API Extension for Source IP Address Selection", draft-sijeon-dmm-use-cases-api-source-07 (work in progress), September 2017. [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E.