-Preface
The purpose of this FAQ is to help readers help themselves by arming them with the knowledge and the know-how to solve their own Xbox Live connection problems. The only way to do this is to inform as to how Xbox Live works, what keeps it working, and what conditions you need to meet to stay connected to Xbox Live. This FAQ will attempt to stay as non-technical as possible while trying to help inform you; however, parts of this will be very technical in nature. That being said, you do not need to understand every aspect of how and why Xbox Live works to be able to solve your own networking problems. This text is just a general reference intended to guide users when identifying and troubleshooting their connection issues. You may not be able to solve every problem you encounter with Xbox Live after this, but you will know more about Xbox Live, be able to help others with some or all of their Xbox Live connection problems, be more able to read and understand instructions from people who attempt to help you fix connection issues, and be more able to solve your own issues as well.
-Note
This FAQ will be organized into sections. At the end of sections, important information and concepts will be re-listed.
-Introduction
For one to know how Xbox Live works, one must know, even in a general sense, how the Internet works. This introduction will provide the background knowledge and information for users new to the lower levels of Internet operation. This section will ensure that you are able to understand the following sections.
The Internet
The internet can be simply defined as an ad-hoc network of computers and other hardware that operate using a set of standard protocols to exchange information.
A protocol is simply a type of internet communication that is standardized throughout the global Internet community. You can think of it as a type of "language" that most (if not all) computers across the world speak and understand. The internet must operate on a standard set of these protocols to allow for proper communication and overall function of the internet.
OSI Model
The OSI Model is a model of the internet and internet protocols organized into seven layers. The purpose of the layer is to define the uses of protocols contained in that layer. To understand this FAQ, you do not need to know the OSI model well, but only to grasp it and the layers it defines.
Layers of the OSI Model
Layer 1 (Physical) protocols provide the physical transport of information.
Layer 2 (Data link) protocols function to provide the procedural means at which to transfer information.
Layer 3 (Network) protocols provide the procedural means of transferring information between more than one network.
Layer 4 (Transport) protocols provide the means to reasonably assure the reliable transmission and receiving of information.
Layer 5 (Session) provides for establishing data exchanges between users.
Layer 6 (Presentation) protocols mainly provide for specific encoding of the information received by a network device.
Layer 7 (Application) directly interfaces with the end user to allow for the transfer of information.
A rather excellent and simple example of the OSI model in real life is the WikiPedia Paralell of the OSI model to the transfer of mail from business executives to fellow business executives.
This FAQ will focus mainly on Xbox Live and your Xbox's interaction with Layer 2, Layer 3, and Layer 4.
Essential information for "Introduction":
Protocol
Layer 2 (Data link)
Layer 3 (Network)
Layer 4 (Transport)
-Ethernet and the MAC Address (Layer 2)
Ethernet
Ethernet is the most commonly used protocol in the data link layer of the OSI model. The network interface card of your computer and your Xbox both communicate with other computers via Ethernet. While the technical specifications of Ethernet are not generally important for the troubleshooting of Xbox Live connectivity, it is necessary to understand the MAC Address, which Ethernet uses to ensure the delivery of data.
The MAC Address
The MAC (media access control) address of your Xbox's network interface card is unique throughout the world (unless of course you've changed it for troubleshooting purposes). Understand that for Ethernet to be able to properly deliver data, the MAC Address of your Xbox must be unique across your local network. Failure to comply with this will ultimately result in network failure. The MAC address is also sometimes used by ISPs to identify changes in the network structure of a customer’s Local Area Network.
Essential Information for "Ethernet and the MAC address"
Ethernet
MAC address
-Internet Protocol (Layer 3)
The internet protocol (IP) is the most commonly used protocol in the network layer of the OSI model. It provides the basis of communication for your Xbox to Xbox Live through addressing, allowing internet routers to properly route information.
IP Routing
IP packets contain information about the destination and source of information. They have a source address and destination address header to allow routing hardware on the internet to route the packet to the proper place.
IP Addresses
The most important thing for us to understand about the Internet Protocol is the IP address.
The IP address is a unique network address that allows IP to send and receive information. All IP addresses on a local network must be unique.
Essential Information for "Internet Protocol"
IP address
General Understanding of Internet Protocol
-TCP and UDP (Layer 4)
TCP
The Transmission Control Protocol (TCP) is used to, with a reasonably high assurance, safely transfer files with a minimal chance of information loss or corruption. TCP is used in conjunction with IP and Ethernet to download Xbox Live auto-updates, and downloadable content.
TCP works by sending information, waiting for verification that the information was received, and then continues to send more information until all necessary information has reached the destination.
UDP
The User Datagram Protocol (UDP) is used to efficiently transfer large amounts of information with a small amount of “overhead”. UDP is used for game play on Xbox Live. The reason that TCP is not used for game play on Xbox Live is the large amount of "overhead" generated by TCP repeatedly checking to make sure that information has reached its destination. UDP does not verify the reception of information by the party it is being sent to, which makes it useful for applications where reception of every packet is not absolutely critical. This is great for online games because it allows gamers to get the most out of the bandwidth they have available to them, even if a certain amount of packets are dropped or lost. If TCP were used to play Xbox Live, gamers would notice considerably more network 'lag' than when UDP were used, depending on the amount of bandwidth allocated to that connection of course.
Ports
Both TCP and UDP communicate on their own set of "ports". Ports can be related to their physical relatives, a harbor. A harbor is used to receive, unload, reload, and send off ships. TCP and UDP ports work in much the same way. A TCP or UDP "packet" of information is sent to another computer using a port that both computers agreed they would send packets or receive packets on. The packet finds its way to the proper address via IP routing, and then the packet finds its way to the port that both computers had agreed on communicating through. The receiving computer waits for a packet to be sent to it, and once it receives it, interprets it and performs any necessary actions after that, such as sending a response packet verifying reception, as TCP does.
Essential Information for "TCP and UDP"
General understanding of TCP and UDP
-Daemons
A daemon (or server) is a program that is setup, waiting to receive specific requests. Daemons are "binded" to specific ports. That is, they wait and listen for a packet to be sent to them on a UDP and/or TCP port assigned only to them. Daemons typically provide a specific service. The most popular daemons are assigned a standard port so that all computers know what port to find a daemon on.
The Xbox, for example, will send a request to the Xbox Live servers to login, using a port specified for the daemon that performs that specific function.
Essential Information for "Daemons"
Definition of a daemon
Operation of a daemon
-Client-Server System
A daemon (or server) is connected to by clients. A client will connect to the server, provide any necessary login details (if applicable) and then be granted access to the services that the client seeks to have the daemon provide.
The Xbox is a client to various services the Xbox Live servers offer when connected to Xbox Live.
Essential Information for “Client-Server System”
Definition of a client
Definition of a server
-DNS
The DNS (Domain Name System) is a protocol that benefits users of the internet by making it possible to contact another computer by the use of user-friendly named addresses--Xbox.com for example--instead of IP addresses, which are strings of numbers that are not as easy to remember as a name. It basically allows a computer to ask a DNS server what the IP address of a named address is.
The Xbox Live servers are assigned DNS addresses by Microsoft. The Xbox, when connecting to Live, is instructed to look up the IP addresses of the Xbox Live servers to start communicating with them. Once it has their IP address, it may start communicating with them.
DNS servers operate on TCP and UDP port 53.
Essential information for "DNS"
DNS
DNS servers operate on TCP and UDP port 53
-DHCP
DHCP or the Dynamic Host Configuration Protocol is a protocol that operates using the client-server system. A DHCP client will send out a “broadcast” to all of the addresses on its IP “subnet” (which will be defined later) and waits for a DHCP response.
DHCP servers provide automatic configuration for the DHCP client computer by assigning IP address, Gateway (defined later), (optionally) the DNS server addresses, and a few other options which we won’t be concerned with right now.
Essential Information for “DHCP”
Definition and basic operation of DHCP
-So What Does All of This Have To Do With Xbox Live?
This may be the big question on your mind right now. Why do I need to know about this? Why does this have any bearing on Xbox Live?
The best way to explain this is to examine a connection to Xbox Live.
You put a game disc into your Xbox. Then you start that game up, find the multi-player menu, and sign in to Xbox Live. But what really goes on here?
Steps for Connecting to Xbox Live
Excluding some protocols we don’t need to worry about, and depending on your settings, your Xbox will first send a DHCP broadcast to all hosts on your subnet, hoping to find a DHCP server running on the network. It will then (usually) receive an IP address from your local DHCP server, if you have one running.
If your Xbox is already configured with an IP address, DNS server address, subnet mask, gateway address, and other possibly necessary information (depending on your connection type), your Xbox will most often continue like this:
Send a DNS request asking your DNS server for two very important Xbox Live server addresses, and wait to receive a reply back.
Initiate a client-server connection to one of these servers on UDP port 88, going through what is called a Kerberos handshake. Essentially, this securely logs you into the Xbox Live servers and allows you to connect to other Xbox Live servers and access the services they provide.
Once your Xbox completes the Kerberos handshake, it is granted various “tickets” by the second server, allowing it to communicate with other Xbox Live servers.
After you have initiated and completed your Kerberos handshake, your Xbox is ready to start downloading necessary information, such as your friends list. It may then start communicating with the game servers and allow you to play multiplayer games with others.
A problem connecting to Xbox Live results in a problem with the completion and success of one or more of the preceding steps.
Essential Information for “So what does this all have to do with Xbox Live?”
Steps for logging onto Xbox Live
-LAN and WAN
LAN or Local Area Network is the network contained within your local area. This usually means the network inside your home or other building. A router will have a LAN interface and a WAN interface. The LAN interface has a different MAC address and IP address than the WAN interface. Typically, the WAN interface is determined by your ISP’s DHCP server or static information you are provided by your ISP. The LAN interface is usually partly assigned by the manufacturer, usually allowing you to change the last two parts (octets) of the IP address.
WAN or Wide Area Network is typically used to describe anything outside of your LAN.
Essential Information for “LAN and WAN”
Definition of a LAN and WAN
-IP addresses, IP addressing, and DNS
One of the most common problems on Xbox Live is a problem with IP or DNS settings. This section will outline IP addresses, IP addressing, and DNS.
Subnets and Subnet Masks
A common problem with users manually assigning their IP settings is the subnet. A subnet (sub-network) mask is used to identify which parts of an IP address define the network, the sub-network, and the host.
The subnet mask cannot be randomly set and be hoped to work. If you use your Xbox behind a router, the subnet mask the router is configured to use is the subnet that the Xbox must be set to use. If you do not use a router or other gateway device on your network, the subnet mask must be the subnet mask your ISP provided you. If you use a subnet mask that differs from the gateway you use, IP packets that should actually be routed to the WAN may be routed inside of your network, where packets that should be routed outside of your network will be routed inside.
IP Addresses and IP Addressing
IP addresses are usually displayed as dotted decimal addresses, like 127.0.0.1
Generally, an IP address contained within the 1.0.0.0 through 126.0.0.0 address range must have the first octet (from where the address begins until the first period) match the first octet of its gateway.
Generally, an IP address contained within the 128.0.0.0 through 191.255.0.0 address range must have the first and second octets of the IP address match the first and second octets of its gateway.
Generally, an IP address contained within the 192.0.0.0 to 223.255.255.0 address range must have the first, second, and third octets match that of its gateway.
So in short, you cannot randomly pick an IP address. They must match certain conditions on the network.
The gateway of your computer or Xbox is the device which your machine directly sends packets of information to if it wishes to communicate outside of its subnet. This device routes this packet to the next necessary network device to allow the packet to reach its destination. The gateway address of a machine must be set properly or you will never be able to send any information outside of your subnet.
IP ranges 10.0.0.0 – 10.255.255.255, 172.16.0.0 – 169.254.255.255, and 192.168.0.0 – 192.168.255.255 are private IP ranges. That is, routers will ship with a choice inside one of those address ranges for the LAN interface address. Most commonly, routers and other networking hardware that support IP are assigned an IP address inside the 10.0.0.0 – 10.255.255.255 and 192.168.0.0 – 192.168.255.255 address ranges. This depends on the vendor.
DNS
DNS, as said before, is used to find the Xbox Live servers addresses on the internet. The DNS server must be a server or network device specifically set to retrieve DNS records, or forward DNS requests to a DNS server.
IP Information
If you pay for a static (non-changing) IP address, your ISP will give you the necessary IP information for your network devices.
If you pay for a dynamic (changing) IP address—the most commonly used IP address type—a DHCP server on your ISP’s network will assign your IP information.
If you use a router or any other network device between you and your local network, which supports IP, it will have a LAN and a WAN IP address. The WAN IP information is either the static IP information your ISP provided you (if you pay for a static IP address), or it is assigned by your ISP’s DHCP server. The LAN address is manually assigned, but usually with a default setting. Your router may also have a DHCP server running on the LAN to allow for automatic assigning of your IP information for network devices running on that LAN.
Essential Information for “IP Addresses, IP addressing, and DNS”
DNS
IP addressing
Subnet mask
-Troubleshooting Self Sufficiency
Knowing what you know, you can identify the location of a problem with your connection to Xbox Live.
Step Two Connection Issues
Connections that fail at step two are IP setting or certain DNS problems. Open the troubleshooter and ask yourself these questions:
If you’re connecting by manually assigning your IP information…
1) Do I have the correct network gateway address?
2) Is my subnet mask correct?
3) Is my IP address on the same subnet as my gateway?
If you’re connecting by using DHCP to assign your IP information…
1) Is there a DHCP server running on my subnet?
2) Is the DHCP server properly configured to send me IP information?
3) Is the DHCP server setting proper information for the network?
If you cannot answer these questions, read through this FAQ again, and if you still can not answer these questions, make a concise and coherent post in the Technical Issues forum.
Step Three Connection Issues
Connections that fail at step three are DNS problems. Open the troubleshooter and ask yourself these questions:
If you’re connecting by manually assigning your IP information…
1) Is the IP address I have configured as my DNS server properly setup to run as a DNS server?
2) Is the network hardware I use properly setup to route DNS requests to my assigned DNS server?
3) Is your network gateway able to properly route your DNS requests to your DNS server?
If you’re connecting by using DHCP to assign your IP information…
1) Is the DHCP server properly configured to assign DNS server addresses?
2) Is the DHCP server properly configured with its own DNS server address?
3) Is your network gateway able to properly route your DNS requests to your DNS server?
If you cannot answer these questions, read through this FAQ again, and if you still can not answer these questions, make a concise and coherent post in the Technical Issues forum.
Step Four Connection Issues
If your connection fails at step 4, ask yourself the following questions:
1) Are my UDP packets being properly routed to the Xbox Live servers?
2) Are the packets the Xbox Live servers send back able to properly reach my Xbox?
If you cannot answer these questions, read through this FAQ again, and if you still can not answer these questions, make a concise and coherent post in the Technical Issues forum.
-Glossary of Terms
Protocol – a standardized “language” that all or most computers, globally, understand
OSI Model – The model that defines the purpose and operation of network protocols
Layer – A section of the OSI model that contains protocols with similar or the same purpose
Ethernet – The most common Data Link Layer protocol which ensures that only specified recipients receive a packet
MAC Address – The address by which Ethernet determines the recipient and source of an Ethernet frame
IP – Internet Protocol, most common protocol in the Network Layer of the OSI model, provides standards for addressing which allows for proper routing of packets
IP Address – The address by which IP determines the source and destination of a packet, of which must be unique on a subnet
TCP – Transmission Control Protocol, one of the most common protocols of the transport layer, relatively assures data integrity when transferred over the network by verifying reception of information, organized into ports
UDP – User Datagram Protocol, one of the most common protocols of the Transport Layer, ensures relatively little overhead when transferring information over a network, but does not ensure data integrity, organized into ports
Daemon – An application that is binded to a specific port to provide a specific purpose for the client of the daemon
Client-Server System – The system in which a client connects to a server, authenticates if necessary, and receives the service that the server (daemon) provides
DNS – Domain Name System, allows for the use user-friendly named addresses as opposed to hard to remember IP addresses
DHCP – Dynamic Host Configuration Protocol, allows for the automatic configuration of IP settings for DHCP clients on a subnet
LAN – Local Area Network
WAN – Wide Area Network
Subnet Mask – Determines the parts of an IP address which determine network, subnetwork, and host
-Closing
After reading and comprehending this, you will be more self sufficient at troubleshooting your Xbox Live connection issues, as well as being more able to follow and understand instructions provided by others who attempt to help you on your way to playing on Xbox Live.
If you have any suggestions, comments, or questions about this FAQ, private message the author, Shadowed Ghost.
However, with respect to personal networking issues, please make sure to read all other relevant FAQs for information; posting the problem in the Technical Issues forum if neccessary. If you are unable to resolve your problem through those avenues, and you wish for me to assist you, please send me a concise and properly spelled Private Message, including all relevant details about your network.
