Network Infrastructure Device Implementer’s Guide - 1
Network Infrastructure Device Implementer’s Guide
Requirements and implementation details for Consumer and Small Business routers, WLAN APs, and residential gateways for systems that run the Microsoft® Windows Vista™ operating system
August 5, 2005 — Version 0.6
Abstract
This paper describes the requirements and implementation details for Consumer and Small Business routers, wireless LAN access points (WLAN APs), and residential gateways to interoperate with the Microsoft® Windows Vista™ operating system.
Windows Vista delivers a number of new and enhanced experiences for home networks, including ease of setup, ease of use, and distribution of digital media throughout the home. Devices that meet the requirements outlined in this paper will deliver the best experience with Windows Vista and other Microsoft products, including Microsoft Xbox® and Windows Media Center Extender, and will receive the benefits of the Windows Vista Logo Program.
The information in this document applies for the Microsoft Windows Vista operating system.
References and resources discussed here are listed at the end of this paper. The current version of this paper is maintained on the Web at:
For questions or comments about these requirements or implementation guidelines, please send e-mail to .
Contents
Introduction
Document Scope
Technology Framework and Definitions
Setup and Configuration
WCN-Config
WCN-FlashConfig
WCN-Config Network
Simple Config Overview
Requirements for Wireless Routers and WLAP APs
Network and Bus Basics
Router IP Basics
802.11 Requirements for Premium Logo (Streaming Media)
Transparent Connectivity
IPv4 NAT
Port Assignment Policy
Port Filtering Policy
IPv6 and Transition Technologies
Private IPv4 Connectivity (Teredo)
Public IPv4 Connectivity (6to4)
Home Router Considerations When Supporting IPv6
Summary
Discovery and Control
Link Layer Topology Discovery
Requirements for WSD, UPnP, and Auto-Bridge Mode Selection
Quality of Service
QoS and qWAVE
QoS Requirements
Resources and References
Appendix A – DHCP Enable Vendor Extension Schema
Appendix B – UPnP Byte Counter Implementation Details
Appendix C – Guidelines Summary
Disclaimer
This is a preliminary document and may be changed substantially prior to final commercial release of the software described herein.
The information contained in this document represents the current view of Microsoft Corporation on the issues discussed as of the date of publication. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information presented after the date of publication.
This White Paper is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS DOCUMENT.
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Unless otherwise noted, the example companies, organizations, products, domain names, e-mail addresses, logos, people, places and events depicted herein are fictitious, and no association with any real company, organization, product, domain name, email address, logo, person, place or event is intended or should be inferred.
© 2005 Microsoft Corporation. All rights reserved.
Microsoft, Windows, Windows Vista, and Xbox are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries.
The names of actual companies and products mentioned herein may be the trademarks of their respective owners.
Introduction
The difficulty in setting up home networks is often cited as the single largest impediment to increased Internet usage and delivery of broadband services. Currently, users are confused by the choices they face in selecting home networking equipment, and are frustrated when they purchase the wrong equipment or when they configure their network incorrectly and their devices or applications fail to work. As a result, mainstream consumers are hesitant to purchase home networking devices and fail to move beyond simple single-PC tasks such as email and Web surfing.
The Microsoft® Windows Vista™ operating system delivers capabilities that change the landscape for home networks and networking device vendors. Windows Vista makes it easy to set up routers, Wireless LAN access points (WLAN APs), and residential gateways that deliver reliable connectivity and security—provided that these devices meet a base level of requirements for interoperating with Windows Vista. This document describes those requirements.
The Windows Vista Logo Program for Consumer routers and WLAN APs creates a single, unified set of requirements across Microsoft. This ensures that vendors can develop products that address multiple scenarios, without being constrained by conflicting requirements. Although these requirements specifically reflect the capabilities and technologies included in Windows Vista, care has been taken to rationalize all Microsoft requirements for routers and WLAN APs. Requirements from Microsoft Xbox®, Windows Media Center, MSN, and Small Business have been unified into one cohesive set to maximize the program’s effectiveness and benefits to partners.
Note: Small businesses experience network setup and connectivity problems similar to those found in consumer home networks. For consistency, this document refers primarily to Home network scenarios; these scenarios are either identical or very similar to those for Small Business networks, and hence one set of requirements addresses both customer segments.
Document Scope
This paper provides the specific requirements and implementation details for vendors who design and produce routers, wireless access points, and residential gateways to interoperate with Windows Vista. Devices that meet the requirements and guidelines in this document will meet the requirements for the Windows Vista Logo Program.
Device Types
This paper describes requirements and implementation details for these types of devices:
- Routers (both wireless and wired)
- Wireless LAN access points (WLAN APs)
- Residential gateways
Definitions of device types are provided in “Technology Framework and Definitions” later in this paper.
Note: In this paper, the term “residential gateway” is not used to denote a separate device class; instead, a residential gateway is treated as a router that includes an integrated broadband modem. To receive a logo for a residential gateway product, vendors must meet the requirements for the router device type. No requirements are defined for the modem functionality in a residential gateway.
Requirements for the following device types are not discussed in this document:
switches, hubs, wireless bridge gaming adapters, broadband modems.
Product Qualification Levels
The Windows Vista Logo Program defines requirements for devices that can interoperation with Windows, and also introduces qualification levels for different types of products:
- The Standard logo ensures baseline compatibility and user experience with Windows Vista.
- The Premium logo is reserved for products that enable and deliver premium experiences.
This document provides additional detail to the individual requirements for the Network device types defined in the Windows Vista Logo Program requirements. This document should be used for design and implementation guidance, and to assist vendors in ensuring that their products will pass the validation tests for Windows Vista Premium or Standard logos.
Note: In cases where logo designations (Standard vs. Premium) conflict between this document and Windows Vista Logo Program System and Device Requirements, Version3.0, the Standard versus Premium definitions in the Windows Vista Logo Program System and Device Requirements take precedence.
In this document, the Standard versus Premium information is denoted as follows:
- “Must” indicates that the item is required for the Standard Logo.
For the Premium logo, items are designated with the phrase “must be implemented for the Windows Vista Premium logo.”
All requirements for both the Standard and Premium logos will be tested as part of the Windows Vista Logo Program test suite.
- “Should” indicates that the item is optional, but recommended.
- “If implemented” indicates that the item must meet specific guidelines only when the feature is implemented in a device, though the feature itself is not required.
Technology Framework and Definitions
The following technology framework summarizes the key networking components in Windows Vista. This framework provides the structure and order for technologies discussed in this document.
Table 1. Technology Framework Summary
Technology Definitions
Bridge
A Data Link layer (L2) device that connects two or more different LAN segments to form a single network segment (also known as a subnet or single broadcast domain). A bridge implements a spanning tree algorithm for network loop detection.
Broadband modem
A Data Link layer (L2) device that bridges a physical broadband WAN interface into Ethernet or USB.
Hub
A Physical layer device that connects multiple wired network nodes together on the same LAN segment. A hub implements a repeater function and is a single Ethernet collision domain.
Network address port translator (NAT)
An IP router that translates the IP addresses and TCP/UDP port numbers of packets as they are forwarded, as defined by RFC 1631. A NAT allows multiple private network computers to use a single public IPv4 address. (See NAT references listed at the end of this paper.)
Definitions of NAT sub-types are as follows:
Full cone
All requests from the same internal IP address and port are mapped to the same external IP address and port. Any external host can send a packet to the internal host by sending a packet to the mapped external address. This NAT type is also be referred to as an “Open” NAT.
Restricted cone
All requests from the same internal IP address and port are mapped to the same external IP address and port. Unlike a full cone NAT, an external host (with IP address X) can send a packet to the internal host only if the internal host had previously sent a packet to IP address X.
Port restricted cone
Similar to a restricted cone NAT, but the restriction includes port numbers. Specifically, an external host can send a packet, with source IP address X and source port P, to the internal host only if the internal host had previously sent a packet to IP address X and port P.
Symmetric (or “strict” NAT)
All requests from the same internal IP address and port, to a specific destination IP address and port, are mapped to the same external IP address and port. If the same host sends a packet with the same source address and port, but to a different destination, a different mapping is used. Only the external host that receives a packet can send a UDP packet back to the internal host. Symmetric NATs do not interoperate properly with Windows and many other operating systems and applications, and should be avoided at all times.
Residential gateway
A device that combines an IP router with a broadband modem, designed to connect a private network to the Internet. Residential gateways that meet the requirements described in this document for routers meet the requirements for the Windows Vista Logo Program, since they contain a full set of router functionality.
Router
A Network layer (L3) device that connects disparate network segments (that is, subnets) and forwards traffic based on a combination of a network address and a node address. NAT functionality must be included.
Note: A router with multiple Ethernet interfaces (or one or more wireless interfaces) does not route between LAN-side interfaces; they are typically switched or bridged. In other words, a home router generally routes only between the WAN and LAN interfaces.
In this document, the term “router” refers to both wired-only routers (those that have only wired Ethernet interfaces) and wireless routers (a router with a wireless access point as one of its LAN interfaces).
Switch
A multi-port store-and-forward device that may also implement MAC address learning to selectively forward frames to switch ports based on the destination MAC address. A switch does not implement a spanning tree algorithm.
Wired router
A router with no wireless (802.11) capabilities.
Wireless bridge gaming adapter
A device that connects an individual Ethernet device to a WLAN. This device type only bridges between wired and wireless media and only implements a station function on the wireless interface. Requirements for this device type are not discussed in this document.
Wireless LAN access point (WLAN AP)
A wireless base station used for hosting infrastructure mode IEEE 802.11 wireless networks. WLAN APs bridge network traffic between wireless clients and a wired network segment. A wireless access point enables one or more wireless stations (clients) to associate to its 802.11 interface.
Wireless router
A router that also contains WLAN AP functionality. A wireless router supports all the functionality defined by both a non-wireless router and WLAN AP.
Setup and Configuration
The Setup and Configuration technology area of Windows Connect Now (as listed in Table 1) delivers effortless and secure-by-default setup of wireless infrastructure devices and wireless clients.
WCN-Config
To ensure that a user has a positive experience configuring a secure wireless home network, it is important that the wireless router and WLAN AP devices designed for use in the home support a consistent, secure method for configuration. These capabilities are provided by implementing one or both of the setup methods provided by Windows Connect Now, known as WCN-FlashConfig and WCN-Config Network.
WCN-FlashConfig and WCN-Config Network are both mechanisms for configuring wireless devices, but they differ in the method used to transfer wireless configuration settings:
- WCN-FlashConfig requires that a physical storage device, such as a USB flash drive (UFD) or CompactFlash storage card, be physically moved between the computer and the device in need of wireless configuration settings.
- WCN-Config Network over Ethernet uses UPnP to transfer settings over the wire.
WCN-Config Network over Wi-Fi transfers settings using wireless in-band (that is, no physical medium is needed for transfer).
WCN-FlashConfig
WCN-FlashConfig first shipped in Windows XP Service Pack 2, and greatly eased the difficulty associated with setting up wireless networks and adding wireless devices to them for the small office/home office (SOHO). WCN-FlashConfig is the technology used by the Wireless Network Setup Wizard in Windows XP Service Pack 2, which can be accessed from the Control Panel as a Networking task, as identified by the following icon.
Figure 1. WCN-FlashConfig icon
WCN-Config Network
WCN-Config Network over Ethernet and over Wi-Fi use the Simple Config protocol for configuration and setup.
Simple Config Overview
Figure 2 depicts the major components and their interfaces as defined by Wi-Fi Simple Config. There are three logical components involved: the Registrar, the access point (AP), and the Enrollee.
- The Enrollee is a device seeking to join a WLAN domain. Once an Enrollee obtains a valid credential, it becomes a member.
- A Registrar is an entity with the authority to issue and revoke domain credentials. A registrar can be integrated into an AP.
- The AP can be either a WLAN AP or a wireless router.
Figure 2. Major Components of WCN-Config Network
Registration initiation is ordinarily accomplished by a user action such as powering up the Enrollee and, optionally, running a setup wizard on the Registrar (PC).
Interface M
This interface is between the AP and the Registrar. Interface M enables an external Registrar to manage a Wi-Fi Simple Config AP. Wi-Fi Simple Config uses a similar protocol for setting up the AP Management interface as for issuing credentials to Enrollee devices.
AP
The AP implements Interface M by:
- Acting as the Enrollee in the Registration Protocol for initial setup with one or more external Registrars. This includes sending its own Discovery message across all appropriate channels (Ethernet and/or 802.11 probe response over Wi-Fi).
- Implementing the Management Interface described in the WFADevice and WFAWLANConfig Service documents. This requires the AP to be a UPnP device that includes support for the Wi-Fi Simple Config proxy service.
- Monitoring 802.11 probe request and EAP messages from Enrollees and converting them to UPnP Event messages according to the method described in the WFAWLANConfig Service document.
Interface A
This interface is between the Enrollee and the AP. The function of Interface A is to enable discovery of the Simple Config WLAN and to enable communication between the Enrollee and Ethernet-only Registrars.
AP
The AP implements Interface A by:
- Sending out 802.11 beacons indicating support for Simple Config and generating Probe Response messages containing a description of the AP.
- Implementing an 802.1X authenticator and the Simple Config EAP method.
- Proxying 802.11 probe request and EAP messages between Enrollees and external Registrars as described in the WFADevice and WFAWLANConfig Service documents.
Requirements for Wireless Routers and WLAP APs
To ensure that devices work well with Windows Vista WCN-Config, WLAN APs and wireless routers must meet the following requirements: