What does Extended Service Set ESS ID mean?
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A service set identifier (SSID) is a sequence of characters that uniquely names a wireless local area network (WLAN). An SSID is sometimes referred to as a "network name." This name allows stations to connect to the desired network when multiple independent networks operate in the same physical area. Show
Each set of wireless devices communicating directly with each other is called a basic service set (BSS). Several BSSs can be joined together to form one logical WLAN segment, referred to as an extended service set (ESS). A Service Set Identifer (SSID) is simply the 1-32 byte alphanumeric name given to each ESS. For example, a departmental WLAN (ESS) may consist of several access points (APs) and dozens of stations, all using the same SSID. Another organization in the same building may operate its own departmental WLAN, composed of APs and stations using a different SSID. The purpose of SSID is to help stations in department A find and connect to APs in department A, ignoring APs belonging to department B. Each AP advertises its presence several times per second by broadcasting beacon frames that carry the ESS name (SSID). Stations can discover APs by passively listening for beacons, or they can send probe frames to actively search for an AP with the desired SSID. Once the station locates an appropriately-named AP, it can send an associate request frame containing the desired SSID. The AP replies with an associate response frame, also containing SSID. Some frames are permitted to carry a null (zero length) SSID, called a broadcast SSID. For example, a station can send a probe request that carries a broadcast SSID; the AP must return its actual SSID in the probe response. Some APs can be configured to send a zero-length broadcast SSID in beacon frames instead of sending their actual SSID. However, it is not possible to keep an SSID value secret, because the actual SSID (ESS name) is carried in several frames. The terms BSSID, ESSID, and SSID are all used to describe sections of a wireless network (WLAN)—the three terms have slightly different meanings. As a wireless user you are concerned only with the broadcast SSIDs that let you connect to a wireless network. As an administrator, you also need to keep track of BSSIDs and, to a lesser degree, ESSIDs. An SSID is the Name of a NetworkBecause multiple WLANs can coexist in one airspace, each WLAN needs a unique name—this name is the service set ID (SSID) of the network. Your wireless device can see the SSIDs for all available networks—therefore, when you click a wireless icon, the SSIDs recognized by device are listed. For example, suppose your wireless list consists of three SSIDs named Student, Faculty, and Voice. This means that an administrator has created three WLAN Service profiles and, as part of each WLAN service profile, provided the SSID name Student, Faculty, or Voice. (For directions to create a WLAN Service profile, see Creating and Managing a WLAN Service Profile.) As a WLAN user, you are concerned only with the SSIDs. You select one from the list on your laptop or other device, provide your username and a password, and use the SSID. You might not have access to all SSIDs—the authentication and access privileges are usually different for different WLANs and their associated SSIDs. BSSIDs Identify Access Points and Their ClientsPackets bound for devices within the WLAN need to go to the correct destination. The SSID keeps the packets within the correct WLAN, even when overlapping WLANs are present. However, there are usually multiple access points within each WLAN, and there has to be a way to identify those access points and their associated clients. This identifier is called a basic service set identifier (BSSID) and is included in all wireless packets. Figure 2: Each Access Point has its Own BSSAs a user, you are usually unaware of which basic service set (BSS) you currently belong to. When you physically move your laptop from one room to another, the BSS you use can change because you moved from the area covered by one access point to the area covered by another access point, but this does not affect the connectivity of your laptop. As an administrator, you are interested in the activity within each BSS. This tells you what areas of the network might be overloaded, and it helps you locate a particular client. By convention, an access point’s MAC address is used as the ID of a BSS (BSSID). Therefore, if you know the MAC address, you know the BSSID—and, because all packets contain the originator’s BSSID, you can trace a packet. This works fine for an access point with one radio and one WLAN configured. Most often, there are different BSSIDs on an access point for each WLAN configured on a radio. If you have an access point with 2 radios and 32 WLANs configured on each, you would have 64 BSSIDs plus the base access point BSSID. To accommodate the multiple BSSIDs, each access point is assigned a unique block of 64 MAC addresses. Each radio has 32 MAC addresses and supports up to 32 service set identifiers (SSIDs), with one MAC address assigned to each SSID as a basic service set identification (BSSID). All MAC addresses for an access point are assigned based on the base MAC address of the access point. NoteThe access point MAC address block is listed on a label on the back of the access point. To view a list of SSIDs for a network, look at the list of WLAN Service Profiles in Network Director. Ad-Hoc Networks Do Not Have a MAC AddressEvery BSS needs a BSSID, and using the access point’s MAC address works fine most of the time. However, an ad-hoc network, a network that forwards traffic from node to node, has no access point. When a BSS does not have a physical access point, in an ad-hoc network for example, the network generates a 48-bit string of numbers that looks and functions just like a MAC address, and that BSSID goes in every packet. An ESS Consists of BSSsAn extended basic service set (ESS) consists of all of the BSSs in the network. For all practical purposes, the ESSID identifies the same network as the SSID does. The term SSID is used most often. What does Extended Services Set ID mean ESS )?An extended service set (ESS) is a wireless network, created by multiple access points, which appears to users as a single, seamless network, such as a network covering a home or office that is too large for reliable coverage by a single access point.
What does ESS mean in WiAn extended service set (ESS) is one or more interconnected basic service sets (BSSs) and their associated LANs. Each BSS consists of a single access point (AP) together with all wireless client devices (stations, also called STAs) creating a local or enterprise 802.11 wireless LAN (WLAN).
What can an Essid be used interchangeably with?In fact, the term ESSID can be used interchangeably with SSID. However, in common practice, the term SSID is used a lot more frequently, so while SSID is definitely a term I want you to know, I also want you to know that it's just another way of saying the same thing. It's another way of expressing an SSID.
What is the difference between a ESS and a BSS?The two types of service sets are Basic Service Set (BSS) and Extended Service Set (ESS). A BSS consists of a group of computers and one AP, which links to a wired LAN. An ESS consists of more than one AP. An ESS lets mobile users roam anywhere within the area covered by multiple APs.
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