Voice over WLAN Design Guide R4.2.1 OmniPCX Enterprise R9.1 ed1, March 2010 Central PreSales Alcatel-Lucent Corporate Communication Solutions All Rights Reserved © Alcatel-Lucent 2010 Central PreSales /DF Voice over WLAN Design Guide Rel 4.2.
1. Introduction & Objectives................................................................................................. 10 1.1. Operational Components ............................................................................................ 11 1.1.1. OmniPCX Enterprise Applications Specific Elements ............................................... 11 1.1.2. WLAN Infrastructure (Provided by Alcatel-Lucent) ................................................... 11 1.1.3.
2.2.1.2.. Overlay Mode 2.2.1.2.1. 35 Overlay Mode Operation .......................................................................... 36 3. Quality of Service (QoS) .................................................................................................. 37 4. Security........................................................................................................................... 38 4.1. SSID Broadcast...............................................................................
6.3. VoWLAN on Remote AP for Home Worker .................................................................... 50 6.3.1. Overview............................................................................................................. 50 6.3.2. Remote AP and Encryption.................................................................................... 51 6.3.3. Implementation with a Corporate Firewall (Security)............................................... 52 6.3.4.
6.8.3.2.. Handover and Roaming in Layer 3 (Single or Multi-WLAN switch) 6.9. 68 G711 considerations ................................................................................................... 69 6.10. G729 considerations ............................................................................................... 69 6.11. Voice over WLAN Design Rules (Alcatel-Lucent WLAN infra) ....................................... 70 6.11.1. Recommended AOS for VoWLAN ...................................
.13.2. Predictive Tool Coverage Planning ........................................................................ 81 6.13.2.1. 7. RF Planner (available from BPWS) 82 Environment Verification & Validation............................................................................... 83 7.1. Compliance with VoWLAN Offer .................................................................................. 83 7.2. Pre Install VoWLAN Radio Coverage Audit (Site Survey) .....................................
11.2. Site Survey Tool Example.......................................................................................... 95 11.3. Embedded Site Survey on MIPT 310 and 610 ............................................................ 96 12. SVP Server Rules (Reminder) ......................................................................................... 97 12.1. DHCP Server ........................................................................................................... 97 12.2.
Figure 17: Double encryption on Remote AP................................................................................ 51 Figure 18: RAP with a corporate Firewall ..................................................................................... 52 Figure 19: DMZ implementation with RAP................................................................................... 53 Figure 20: Mesh Bridging with VLANs..........................................................................................
Central PreSales Voice over WLAN Design Guide Rel 4.2.
1. Introduction & Objectives It is the intent of this guide to aid Sales Engineers in designing and selling telecommunications solutions Incorporating Alcatel-Lucent’s Mobile IP Touch (MIPT) Voice over Wireless LAN (VoWLAN) solution This document has been created specifically in the context of an architectural and technical Pre-Sales Design Guide approach.
1.1. Operational Components The Alcatel-Lucent MIPT VoWLAN solution offer is comprised of many subcomponents. These components can be easily grouped into their categories defined by their functions and responsibilities. 1.1.1. OmniPCX Enterprise Applications Specific Elements At the core of Alcatel-Lucent’s MIPT VoWLAN offer lays the Alcatel-Lucent OmniPCX Enterprise platform (R9.0) Key to enabling the capabilities of Alcatel-Lucent’s VoWLAN solution is the NOE features. 1.1.2.
OmniAccess 4308 Used to support: up to 16 AP OmniAccess 4308 up to 256 users Equipped with eight 10/100 Ethernet ports (802.3af capable). Two different models providing either one 1000base-T Gigabit uplink (Copper) or one 1000base-SX Gigabit uplink (Fiber). Embedded Stateful Inspection firewall options allow for robust security installations.
OmniAccess 6000 (Sup Card 3) Four slot modular chassis used to support: Up to 2048 AP (LAN Connected) Up to 8192 Remote AP/Mesh AP Up to 4 Supervisor Cards Up to 32768 users Supervisor Card 3: up to 512 AP LAN Connected up to 2048 Remote AP/Mesh AP OmniAccess 6000 Sup Card 3 - 10x 1000Base-X (SFP) - 2x 10GBase-X (XFP) Imbedded Stateful Inspection firewall options allow for robust security solutions.
OmniAccess AP60 and AP61 Single radio (802.11a or 802.11b/g) Wi-Fi Access Points for use with OmniAccess WLAN controllers. - AP60 model requires external special purpose antenna (no internal antenna) - AP61 offers only internal antennas OmniAccess AP60 & AP61 OmniAccess AP65 Dual-radio Flexible multifunction Access Point provides simultaneous access to both 802.11a and 802.11b/g radios. Dual, integral, tri-band, high-gain, omnidirectional antennas with 180 degrees rotational movement. Non-detachable.
OmniAccess AP120 and AP121 Single radio IEEE 802.11n (draft 2.0) wireless access point with 2 x 10/100/1000Base-T (RJ-45) Ethernet interface (Supports Power over Ethernet) Optional license for operation in 802.11a or b/g AP120: support for selectable 802.11'B/G/N' or 802.11'A/N' operation, 3x3 MIMO dual-band RP-SMA detachable antenna interfaces. (no internal antenna) OmniAccess AP120 & AP121 AP121: embedded 3x3 MIMO dual-band antenna OmniAccess AP124 and AP125 Dual radio IEEE 802.11n (draft 2.
1.1.3. Server Elements (DHCP, TFTP, Management) 1.1.3.1. DHCP Server Customers have two IP address allocation schemes to choose from for MIPT handsets, static mode and dynamic mode. Static mode operation is very simple and requires no expanded explanation. Terminals are simply programmed manually with IP addresses, subnet mask, default gateway, and TFTP server information. Optionally, MIPT Terminals can be configured in a dynamic mode via standard DHCP server options.
1.1.3.3. RF Director Management The initial goal of RF Spectrum Management is to configure and calibrate radio settings for the wireless network. After the radio network is operational, the goal of RF Spectrum Management changes to that of tuning and adjusting radio parameters in order to maintain a high degree of performance. With AlcatelLucent, RF Spectrum Management is largely automatic, requiring little configuration or intervention from the administrator.
1.1.4. Mobile IP Touch Terminals 1.1.4.1. General Description Alcatel-Lucent makes two new models available, one each for office (MIPT 310) and industrial use (MIPT 610). The performance of these two handsets is very similar but their designs and options are focused for use in specific environments. Both of these terminals are products of an OEM partnership between Alcatel-Lucent and Polycom (former SpectraLink) Main physical changes on MIPT310/610 terminals: • 802.
1.1.4.2. Technical characteristics 1.1.4.2.1. General Specification Radio characteristics Radio frequency 802.11b et 802.11g : 2,4GHz-2,4835Ghz 802.11a : 5,15GHz – 5,35Ghz & 5,47-5,725 in Europe 5,15GHz – 5,35Ghz & 5,725-5,825 in US Transmission type Direct Sequence Spread Spectrum (DSSS) for 802.11b OFDM for 802.11g/802.11.a Transmit data rate 11, 5.5, 2, 1 Mb/s for 802.11b (Auto rate selection) 54,48,36,24,18,12,9,6,11,5.5,2,1 Mb/s for 802.11g 54,48,36,24,18,12,9,6 Mb/s for 802.11.
1.1.4.2.2. Set features MIPT310 MIPT610 Physical characteristics Dimensions Weight with standard battery 22x50x137 mm 22x50x145 mm 4.2ounces (110 gr) 6.
MIPT310 MIPT610 Keypad Navigator 4 way navigation key , in WLAN R 4.
1.1.4.3. MIPT Menu 1.1.4.3.1. Key navigation The keypad is composed of 16 keys, 5 navigator keys and 3 keys on the side. Key/Soft Key Action Up/Down side key Display previous/next menu item. Select side key Selects the menu item or option. OK soft key Selects the menu item or option. Save soft key Saves the entry. Bksp soft key Backspaces to allow editing of entry. Cncl soft key Cancels edit and returns to previous menu level.
1.1.4.3.2. Local standby menu The Local Standby menu allows the user: to customize the phone options (ring parameters, languages, PTT parameters, set contrast, enable/disable keypad lock, etc…), to have access to handset configuration information (firmware version, handset IP @, TFTP @, CPU IP @, etc…). This menu is available in French, English, Spanish, german, dutch, Portuguese and Italian. The Local Standby menu is only available when the handset is in standby mode (ie.
1.1.4.3.4. PBX menu The [Menu] softkey gives access to the menu-driven functions and services proposed by the PBX. The features and services available can be viewed and activated through the displayed menu. The PBX menu is available when the handset is in the standby mode (ie. extension number is displayed). The PBX displayed supported languages are : French, English , Spanish, German, Dutch, Portuguese, Italian, Cyrillic and Greek.
1.1.4.4. PBX services 1.1.4.4.1. PBX features MIPT set uses integrated NOE features (dial by name, notification for messaging, multi-line, multiple calls, normal/casual conference, enquiry call, transfer, call parking, automatic call back, different forwards, voice mail access, send/read text message, etc…) and as a result can be globally considered as an IP Touch set, but limited by its ergonomics (a part of boss/assistant features , no MLA, no key programming, no interphony, etc…).
Software updateserver: A software delivery is composed of 5 files with size estimation : slnk_cfg.cfg Config File (1K byte) pd14cno.bin Functional Code (1024K bytes) pd14odno.bin Over the air downloader (512K bytes) pd14udno.bin USB Downloader (192K bytes) pi1400no.bin Phintl : fonts & labels content (256K bytes) Only the TFTP server IP address (for download) is used to retrieve the files listed above. The terminal always starts with the “slnk_cfg.cfg” file. There are four attempts to download this file.
1.1.4.5. Voice over WLAN offers: handset packs and options Mobile IP Touch 310 Pack: REF 3BN78140AA This pack includes the MIPT 310 handset, the standard battery and the desktop charger. NOTICE: The power supply of the desktop charger must be ordered separately Mobile IP Touch 610 Pack: REF 3BN78141AA This pack includes the MIPT 610 handset, the standard battery and the desktop charger.
Carrying case in black color (Ref: 3BN78151AA) Remarks: the carrying case is compatible with both MIPT 310 and 610 WLAN handsets. Lanyard for Alcatel-Lucent IP Touch 310 & 610 WLAN handset (Ref: 3BN78155AA) Single charger (Ref 3BN78142AA): In-charger dialing.
Quad charger (Ref 3BN78144AA):: LED indicator Designed for easy Battery Pack removal Wall mounted Note: Specific power supply for quad charger.
2. Architectures 2.1. Non-Alcatel-Lucent WLAN based Architecture Warning: SVP server is still required for Non-ALU WLAN infra The implementation of the Alcatel-Lucent VoWLAN solution (MIPT) on a Non Alcatel-Lucent WLAN infra (Aironet, Nortel, Trapeze, etc.) may involve some limitations in terms of VLAN, Roaming & Handover, quantity of calls per AP, QoS, Security etc. Only Alcatel-Lucent WLAN infrastructure and approved third-party infrastructure components are supported.
Following is Polycom URL for VIEW Certified partners/compatibility list and related configuration notes http://www.polycom.com/partners/partner_programs/view_certification_program/view_partners.html Central PreSales Voice over WLAN Design Guide Rel 4.2.
Only VIEW certified topologies from Polycom are supported by Alcatel-Lucent http://www.polycom.com/support/voice/wi-fi/view_certified.html Warning: Check Polycom WEB site regularly for latest updates Note : VoWLAN topologies studied in this document are exclusively built on Alcatel-Lucent WLAN infra. For Non-ALU WLAN infra topologies and restrictions please refer to Polycom configuration notes. Central PreSales Voice over WLAN Design Guide Rel 4.2.
2.2. Alcatel-Lucent WLAN based Architecture Some considerations must be taken under account when implementing the ALU VoWLAN solution. Com Server, WLAN switch, Access Points and MIPT sets must be provided by AlcatelLucent. The edge switch must be POE compatible (AP power feeding). The edge switch and the core switch can be either provided by ALU or coming from other vendors. Nota: SVP server, although still supported, is not needed anymore when using an AlcatelLucent WLAN infrastructure.
2.2.1. Access Point Modes of Operation Being as no two customer network environments are exactly the same, it is critical for technology such as VoWLAN to possess a great degree of flexibility. Alcatel-Lucent’s MIPT solution is not exempt from this requirement. The following section highlights some MIPT architectural adaptabilities. 2.2.1.1.
2.2.1.2. Overlay Mode In Overlay Mode operation, Access Points are not directly attached to Alcatel-Lucent OmniAccess Wireless Switches. In this type of operational mode, the Alcatel-Lucent OmniAccess Wireless Switch acts only as an Access Point Controller and does not directly host AP via local 10/100 ports. This type of operation mode can be highly desirable and advantageous in the following situations: 1.
2.2.1.2.1. Overlay Mode Operation While OmniAccess Wireless Switches can support Direct-Attach mode operation, they can also be used for Overlay mode scenarios. In this way, Access Points can be directly connected to an existing LAN infrastructure Ethernet data switch (from Alcatel-Lucent or third party supplier.
External Power Supply 3. • Inline Power Injectors can be used to provide IEEE 802.3af power to individual Access Points. These low-cost, single port (one in, one out) injectors can be used in situations where only one or a few devices require power. These devices require a local AC outlet connection to produce IEEE 802.af power and then inject Inline Power Injector this power along with the Ethernet traffic that pass transparently through it.
4. Security Security is always a sensitive topic to discuss, and opinions on how best to provide for it vary greatly from one engineer to the next. With this in mind, Alcatel-Lucent is constantly developing the list of security options available within the MIPT VoWLAN solution offer to satisfy as many different opinions as possible. For the Voice over WLAN R 4.1 solution offer, Alcatel-Lucent makes the following security recommendations: 4.1.
In order to minimize the re-authentication delay the following methods are used: OKC (Opportunistic Key Caching) Available on ALU WLAN infra (OKC on MIPT with WPA2 only) CCKM (Cisco Centralized Key Management) Available on Cisco AP only 4.3.
4.4. Ekahau RTLS Ekahau RTLS (Real-Time Location System) provides a geo-localization of MIPT sets within a building or an outdoor RF covered area, is made of a server (Ekahau Positioning Engine) and a client that is embedded on MIPT set. Ekahau RTLS solution is managed via AAPP (Alcatel-Lucent Application Partner Program) and is only supported on ALU/Aruba WLAN infra.
Pre Shared Key is used for initial authentication and as the seed for Temporal Key Integrity Protocol key rotations. WEP is recognized as being a weak security option due to the static nature of the encryption key. Derivation of the key is possible through simple passive scanning techniques and data analysis. To counter this problem, the Wi-Fi Alliance has defined a standard known as WPA. WPA, in reality, is WEP enhanced with TKIP key rotation.
4.9. Layer 3 & 4 Filtering (ACL & Packet Inspection) It is assumed that the VoWLAN environment will be hosted on a customer network which also supports data networking environments. To assure privacy and system security, security controls should be implemented at network routing points to restrict the ability of non-voice related elements from gaining access to VoWLAN and OmniPCX Enterprise components.
5. Design Process for VoWLAN 5.1. Pre Sale Data Collection In order to prepare an Alcatel-Lucent VoWLAN solution, several pieces of documentation must be sourced from the customer. The accuracy of a final system proposal is directly related, in most cases, to the amount and quality of information collected prior to initiating design formulation. 5.1.1.
5.1.2. Logical Diagram Logical Diagrams are also critical for complete and accurate solution construction. The logical diagram must include information related to the existing customer VLAN strategy, QoS policies, Security measures, redundancy and fault tolerance schemes, as well as future provisioning and traffic shaping.
5.1.3. Floor Level Maps/Diagrams To complete detailed planning, a floor level diagram is required. This floor level diagram can be used in the design process in two different ways, Prediction Planning and for the Site Survey. This diagram does not necessarily need to include detail on how desks are situated within office and where toilets and potted plants are located within restroom, but walls, dividers, elevators, pillars, windows, doors, and other obstacles should be clearly marked and to scale.
6. Customer Specific Application & Design Considerations Due to the fact that Alcatel-Lucent’s MIPT VoWLAN solution is being offered in a multi-stage fashion with evolving capabilities, it is important for the design engineer to compare expected customer usage patterns against current MIPT release restrictions before proposing an Alcatel-Lucent MIPT VoWLAN solution. 6.1.
– 6.1.4. Single OXE Node in a Multi-Site Environment (Campus / Remote Site) Figure 9: Single-OXE Node and Multi-Site This topology based on a single OXE node allows a VoWLAN implementation on remote sites. For Roaming and Handover restrictions in campus or remote site see the chapter dedicated to Roaming & Handover. 6.1.5. Multi OXE Node in a Multi-Site Environment (WAN) Figure 10: Multi-OXE Node and Multi-Site Same configuration as previously, but now in an OXE Multi-node OmniPCX topology.
6.1.6. Multi-WLAN Switch Layer 2 Configuration Figure 11: Layer 2 configuration (WLAN switch) Layer 2 configuration means that all WLAN switches are in a unique VLAN/IP subnet and MIPT sets are all in the same Voice VLAN/IP subnet. This topology allows quick handover. 6.1.7.
Figure 13: Layer 3 configuration for WAN Layer 3 configuration is also applicable to WAN topologies 6.2. Remote LAN-connected AP Figure 14 Remote LAN-connected AP A Remote LAN-connected AP is a standard AP that is installed on a remote site and interconnected to the central WLAN switch via a GRE tunnel. This configuration is not supported with MIPT due to voice tromboning over the WAN. Central PreSales Voice over WLAN Design Guide Rel 4.2.
6.3. VoWLAN on Remote AP for Home Worker 6.3.1. Overview Figure 15: Remote AP for Home worker A Remote AP is an AP that is installed on a remote site but with a specific Remote AP license configured on central WLAN switch. During the provisioning (where the Remote AP is locally connected to the WLAN switch) a VPN tunnel is automatically raised between the Remote AP and the central WLAN switch.
6.3.2. Remote AP and Encryption Figure 16: Encryption on Remote AP Figure 17: Double encryption on Remote AP From the above pictures an IP Touch set is plugged into the Eth port 1 of the AP70 (configured as RAP). Two SSIDs are created: SSID1 with WPA2 crypto (MIPT) SSID2 with open crypto/auth (Wireless PC) All traffic from wired users connected to Eth1 is always encrypted – independent of the “double encrypt” configuration.
6.3.3. Implementation with a Corporate Firewall (Security) Figure 18: RAP with a corporate Firewall This above picture shows how to implement a remote AP access with a corporate firewall, the purpose of this topology being to hide the corporate network from the Internet. The IP Sec VPN Tunnel created between the remote AP and the WLAN switch must go through the Corporate Firewall. A NAT Traversal function for IPSec Tunnel is performed by the firewall.
6.3.4. Implementation in a DMZ (Security) Figure 19: DMZ implementation with RAP This implementation is fully adapted when the customer requires that any VPN tunnel ends in a DMZ (Demilitary Zone). In this case the Local WLAN switch ensures a VPN termination in DMZ and is in charge of remote APs only. The Master WLAN switch in Corporate Network manages local APs and communicates with the local WLAN switch via the Corporate Firewall. Central PreSales Voice over WLAN Design Guide Rel 4.2.
6.4. VoWLAN Mesh in 802.11a b/g Mesh function is subdivided in two separate features: Mesh Bridging and Mesh Backhaul. Indoor mesh or outdoor mesh can be used depending on license installed on WLAN switch (Indoor Mesh Point License or outdoor Mesh Point License)and the type of AP. For instance an AP70 needs an Indoor Mesh Point license while an AP85 requires an outdoor Mesh Point license. A mesh license is required whatever the function is, mesh portal or mesh point. 6.4.1.
6.4.2. Mesh Backhaul Mesh Backhaul purpose is to extend RF coverage through a wireless mesh link. WLAN services (local coverage) can be either done on the mesh point only or on the both mesh portal and mesh point. 6.4.2.1. Mesh Backhaul on a single Radio Figure 21: Mesh Backhaul with a Single Radio Mesh link and WLAN services, the both being on a Single Radio are supported from AOS 3.4.0. Selected radio can be either 802.11a or 802.11b/g. On this above example 802.
6.4.2.2. Mesh Backhaul using dual Radio Figure 22: Mesh Backhaul using two Radios Using one Radio for Mesh Link and another Radio for WLAN Services is still valid: Mesh link in 802.11b/g with WLAN services in 802.11a, or Mesh link in 802.11a with WLAN services in 802.11b/g. A dual-radio is required for Mesh Point AP. If Mesh Portal AP provides WLAN services a dual-radio AP is required, if not a single-radio AP for Mesh Portal is enough. Voice and Data wireless users must share the same Radio.
6.4.3. VoWLAN Mesh Rules Figure 23: First VoWLAN Mesh rule First rule: 2 Voice Mesh Hops max. Let us consider the above topology (made of one mesh portal and 2 successive mesh points) and assume that the true bandwidth is 20 Mbps between mesh portal and the first mesh point, this bandwidth will be divided by 2 when reaching the second mesh point. It is due to the fact that the first mesh point has 2 mesh links to manage. Figure 24: Second VoWLAN mesh rule Second rule: 3 Voice Mesh directions max.
Third rule: a Mesh portal supports up to 6 Mesh points max Figure 25: Third VoWLAN mesh rule Figure 26: Combining VoWLAN mesh rules All combinations are possible as long as the 3 rules are observed: 3 directions max, 2 hops max and up to 6 Mesh Points. Warning: The Global call transit capacity of the Mesh Portal AP has to be shared between all Mesh Points Central PreSales Voice over WLAN Design Guide Rel 4.2.
6.5. VoWLAN Mesh in 802.11n 802.11n is available for Mesh from AOS 3.4.0 for Backhaul and LAN Bridging solutions 802.11n Mesh can be based either on 802.11 a/n (5 GHz) or 802.11 b/g/n (2.4 GHz) 802.11n Mesh Backhaul can either use a single Radio for the both Mesh Link and WLAN services, or one Radio for Mesh Link and another radio for WLAN services 802.11n Mesh Benefit is throughput improvement. Following are some test results performed by Alcatel-Lucent validation.
Validation test results: Data throughput in 802.11 a/n Radio: 802.11a/n on mesh link Scenario TCPDownstream TCPUpstream UDPDownstream UDPUpstream Data traffic alone 64 Mbps 52 Mbps 23 Mbps 22 Mbps 6.6. VoWLAN on AP85 AP85 is available for Voice over WLAN (MIPT) for the following topologies: - Outdoor LAN-Connected AP - Outdoor Mesh Backhaul - Outdoor Mesh LAN bridging AP85 can operate in 802.11a and 802.11bg simultaneously. On each radio 2 connectors are available in order to perform diversity.
6.7. 802.11n 6.7.1. Overview 802.11n is a standard supplement to increase the throughput in 2.4 GHz & 5 GHz radio bands in order to reach very high data rate up to 300Mbps. 802.11n technology is based on MIMO (Multiple-Input-Multiple-Output) technology that takes advantage of multipath effects. MIMO is defined as MxN: e.g. 2x2, 3x3 and up to 4x4 M = number of transmit antennas N = number of antennas at the receiver. 802.11n improves RF coverage of 30% when using 802.11n clients only and can run in 2.
6.7.2. 2.4 GHz channel aggregation for 802.11n Figure 28: Channel aggregation in 2.4GHz 802.11n can operate either in 20 MHz or 40 MHz. Channel aggregation made of 2 channels is possible in 2.4 GHz (802.11 b/g /n) but makes the AP implementation difficult to avoid interferences between APs. As a reminder channels 1, 6 and 11 must not interfere.
6.7.4. MIPT interoperability between 802.11n and “Non n” APs Figure 30: Interoperability 802.11n and 802.11a b/g MIPT is not a 802.11n client and so does not support native 802.11n operation. Due to the fact that 802.11n AP is backward compatible with 802.11 a b/g, a MIPT set supporting 802.11 a b/g can interoperate with a 802.11n AP. 802.11n does not increase bandwidth for MIPT, because the MIPT still operates in 802.11a or b/g. Central PreSales Voice over WLAN Design Guide Rel 4.2.
6.7.5. General Recommendations for a 802.11n Deployment 802.11n implementation should be a green field allowing fewer APs as long as all clients are native 802.11n. Gigabit support is mandatory for AP Ethernet connection due to the larger bandwidth involved by MIMO operation and channel aggregation: - GB Ethernet ports, GB Ethernet cabling, GB controller throughput New access points to support 802.11n: AP120, AP121, AP124 & AP125 New power sources for 40MHz support (Dual-channel): PoE+ followed by 802.
6.7.7. VoWLAN Use Case in 802.11n Purpose of this section is to describe an implementation scenario mixing WiFi customer needs in 802.11a, 802.11b/g and 802.11n. In a recent past (before 802.11n) the recommendation was having Voice over WLAN (MIPT) in 802.11a and wireless data in 802.11b/g, provided the fact that dual-radio access points were deployed. Today 802.11n implementation modifies a little bit the rules. Following is a scenario example: 6.7.7.1.
6.7.7.3. Voice site survey (use case) - A Voice site survey must be performed in 802.11a with a minimum RSSI level of -60 dBm. - Floor maps for involved buildings must be provided and also the areas to be covered in WiFi - Quantity of voice/data users per zone/area or room are also required. 6.7.7.4.
6.8. Roaming and Handover 6.8.1. Roaming definition Refers to the ability to be reached (ie: making and receiving calls) in a different Site or Network. Inside a site or a network, provides a wireless device the capability to associate to an AP after a power-on or a reset of this device. 6.8.2. Handover definition Refers to the ability to move from one AP coverage area to another AP without service disruption or loss in connectivity. 6.8.3.
6.8.3.1. Handover and Roaming in Layer 2 (Single or Multi-WLAN switch) MIPT Layer 2 Handover and Roaming are supported on a single or a multi-WLAN switch topology 6.8.3.2. Handover and Roaming in Layer 3 (Single or Multi-WLAN switch) MIPT Layer 3 Handover and Roaming are supported on a single or a multi-WLAN switch topology Note: in the recent past, there was a Multi-Switch handover issue with AOS 3.
6.9. G711 considerations Figure 31: G711 This topology fully based on G711 does not contain any compression. This configuration is supported but requires a large bandwidth on WAN (no Voice compression). In this example G711 is permanently used whatever the call destination is (intra-node or extra-node). 6.10. G729 considerations Figure 32: G729 This topology based on G729 allows compression on wan for MIPT 310/610 sets. (MIPT set supports G711 and G729 only, but not G723).
6.11. Voice over WLAN Design Rules (Alcatel-Lucent WLAN infra) Alcatel-Lucent MIPT 310 and MIPT 610 VoWLAN terminals support the following radios: - 802.11b - 802.11g - 802.11a No SVP server need As a reminder legacy MIPT 300/600 are not supported without SVP server 6.11.1. Recommended AOS for VoWLAN As part of VoWLAN 4.2.1 the AOS 3.4.1.1 has been used by validation. Please check from BPWS the latest recommended AOS version to use for VoWLAN 6.11.2.
6.12. WLAN Licensing Some important changes occurred in the way to apply WLAN licenses, depending on the type of WLAN switch family that is involved. 6.12.1. WLAN Licensing with Original WLAN switch Family (AOS 3.4.1) 6.12.1.1.
6.12.1.2. License Main Rules (Original Switch Family) MAP and RAP LAN-connected AP, MAP and RAP, each counts for 1 AP Mesh Portal and Mesh Point count for 1 AP each Redundancy Licenses are also required on Redundant switch 6.12.1.3. License Calculation Example with OAW-4324 OAW-4324 has a capacity of 48 (LAN-connected) APs 48 LAN-connected AP, or 48 RAP, or 48 MAP 24 LAN-connected AP + 16 RAP + 8 MAP (24 + 16 + 8 = 48) Multiple possible combinations… Central PreSales Voice over WLAN Design Guide Rel 4.
6.12.2. WLAN Licensing with New WLAN Switch Family (AOS 3.4.1) 6.12.2.1.
6.12.2.2.
6.12.2.3.
6.12.4. Roaming and Handover Roaming and Handover are topology dependent (see chapter Roaming and Handover)and require: - A common SSID - Common Security rules to be applied to all WLAN switches (Same WEP key or WPA/WPA2 passphrase) 6.12.5. Converged Wireless Environments (Voice & Data Combinations) One of the most significant reasons that businesses look to use wireless LAN technology to support voice is the desire to have a single infrastructure for both voice and data services.
6.12.5.3. Voice on 802.11g, Data on 802.11a This implementation is still possible but may be not fully adapted as many laptops and wireless PCs are still equipped with embedded 802.11g wireless cards. 6.12.5.4. Voice on 802.11a, Data on 802.11g Because IEEE 802.11a utilizes the 5 GHz wireless spectrum that fits VoWLAN needs, it offers no direct radio competition to Data Wireless solutions that require use of the 2.4 GHz IEEE 802.11g realm.
6.12.5.5. Simultaneous Calls per AP with a concurrent Data traffic of 5Mbps This table shows the test results done with a concurrent Data traffic of 5 Mbps on the same Radio in each case (Bandwidth sharing between Voice and Data on 802.11b, 802.11g and 802.11a) . 6.12.5.6. Partially Overlapping Voice and Data Networks on 802.11b/g (isolated applicability) In some cases, a customer may implement 802.11 g for voice and choose to restrict Wi-Fi data client access for security or productivity reasons.
6.13. Predictive Environment Solution Options (Responding to RFx) When answering an RFP or RFI, normally, there is little possibility of scheduling a Site Survey for various reasons: Building under construction or not yet built, short delay to answer the RFP, fair competition clause, etc. In these cases we can make a compromise between absolute accuracy of design and ease of offer presentation by trying to evaluate the user environment and theorize the required quantity of Access Points.
Calculating Access Point Quantity • • • Drywall building with a theoretical bandwidth of 18 Mbps for 802.11a (-65dBm) Determine Radius & Z factors: R=~11.5m Z=~16.5m Z²=~250m² (approximated with margin of error) Divide the building floor in rectangles and calculate the number of AP by dividing the area of each rectangle by Z²: Figure 34: Predictive Method: AP Calculation Example Results: Area 1 => Quantity of AP = (31 x 31)/250 = 3.
6.13.1.1. Predictive Coverage chart example for 802.11 b/g and 802.11a This chart provides additional indications about building coverage for 802.11b/g and 802.11a for data, but keeping in mind the RSSI levels required for Voice over WLAN For more details see the chapter: Required RSSI levels for a Voice Site Survey (VoWLAN) 6.13.2.
6.13.2.1. RF Planner (available from BPWS) The offline RF Plan application provides tools for pre-deployment RF planning. RF Plan allows you to determine access point placement based on your specified coverage and capacity requirements without impacting the live network. Using this tool, you can design new wireless network areas, such as campuses, buildings, and floors, and enter settings to provision and connect access points (APs) and/or air monitors (AMs) within the areas.
7. Environment Verification & Validation After collecting information on the customer data networking environment from both a logical and physical perspective, and evaluating the customer voice communications needs; it becomes important to verify and validate the collected information. These operations are not meant to be insulting to a customer or business partner, nor are these practices meant to be “revenue generation” tactics.
7.3. Post Install Survey Wireless networks are often changing to meet new application demands, business processes, or in response to external influences (neighboring networks and other spectrum disturbing sources.) For this reason, Alcatel-Lucent recommends regular radio coverage surveys in order to continuously revalidate system operation.
8. Design Examples 8.1. Configuration for up to 4 AP & 8 AP (Demo & small area coverage) This configuration example depicts a model well adapted to a Demo context for up to 4 AP without a customer need for WLAN controller redundancy. Figure 35: Config for up to 4 AP (no redundancy) Central PreSales Voice over WLAN Design Guide Rel 4.2.
8.2. Configuration for up to 16 AP (No redundancy) This example depicts a model for up to 16 AP without a customer need for WLAN controller redundancy. Figure 37: Configuration for up to 16 AP (no redundancy) Depending on needed bandwidth a Fast-Ethernet port or a Gigabit port can be used to join LAN. 8.3. Configuration for up to 16 AP (with redundancy) This example depicts a model for up to 16 AP with WLAN controller redundancy.
8.4. WLAN Switch Redundancy Figure 39: WLAN Redundancy (VRRP) 8.4.1. Master Switch Redundancy (Active-Backup only) based on VRRP Active Master switch and Backup Master switch must be both in the same IP subnet due to VRRP operation. Same consideration for the Active Local switch and the Standby Local switch that must be both in the same IP subnet (VRRP). Note: Active-Active redundancy is not supported on Master switch 8.4.2.
8.4.4. WLAN Redundancy with Local Mobility Switch (LMS) Figure 40: WLAN Redundancy with LMS LMS-IP/BACKUP-LMS-IP Each access point is managed by an OmniAccess WLAN mobility controller/switch. This switch is then called the “LMS” (Local Mobility Switch) for this access point and the IP address used by the access point to connect to is referred to as the “LMS-IP”.
8.4.5. Local WLAN Switch operation in case of Master WLAN Switch Failure In case of Master WLAN Switch failure, a Local WLAN can continue to operate but with limited capabilities: - No possibility to modify the Local switch configuration - If an Access Point is turned off or disconnected from Local switch it can not boot anymore - 802.1X authentication cannot be applied to new users on Local switch even if there is a local Radius server.
9. Quotes & Orders Unfortunately, the quotation process for the Voice over WLAN solution is not fully automated within ACTIS as many of Alcatel-Lucent’s other voice technologies. For this reason, engineers are strongly encouraged to complete the framework of the target VoWLAN design prior to beginning the ACTIS process. All hardware components must be manually selected from the VoWLAN SERVERS and IP MOBILE SETS menus (within Mobility Others page.
10. Reference Documents The documents related to the MIPT VoWLAN solution can all be found on the Business Partner Web Site. Here are the related links: 10.1. VoWLAN section of the PreSales Presentations: BPWS Path: • KD_13_VoWLAN_Features_R4-1 OXE_9-0_ed2.ppt (includes How to Quote section) • KD_14_VoWLAN_Features_R4-2-1_OXE_9-1_ed2 • KD_15_WLAN_licensing_ed1 Central PreSales Voice over WLAN Design Guide Rel 4.2.
10.2. VoWLAN section of the PCS Process (non-Alcatel-Lucent WLAN infra): BPWS Path: • VoWLAN PCS Process Information Form 10.2.1. Multi-Vendor section for compatibility: • http://www.spectralink.com/consumer/resources/wifi_compatibility.jsp 10.3. Technical Knowledge base (Technical Communications) 10.4. Release Notes (AOS) Central PreSales Voice over WLAN Design Guide Rel 4.2.
11. Annex 11.1. Site Survey Tool •The Site Survey Tool is a portable engineering tool for measuring and monitoring the air interface of Wireless Local Area Networks (IEEE 802.11). This Tool helps to determine: • The quantity of needed Access points • The correct placement for these Access Points Figure 41: Site Survey components The Site Survey tool is mainly used by Alcatel-Lucent Professional Services and Business Partners.
Figure 42: Survey Result The above picture shows a site survey result done in 802.11a. Just compare the color to the scale. The Target is to obtain a signal strength of –60 dBm or better required for MIPT set operation. Central PreSales Voice over WLAN Design Guide Rel 4.2.
11.2. Site Survey Tool Example http://www.ekahau.com/ Note: This Site Survey software is not orderable from Alcatel-Lucent Central PreSales Voice over WLAN Design Guide Rel 4.2.
11.3. Embedded Site Survey on MIPT 310 and 610 The MIPT embedded Site Survey is also present on MIPT 310 and 610. This mode requires to reboot the MIPT (offline mode). The MIPT site survey mode provides the RSSI level of up to 4 neighboring APs. It can be used at any time to evaluate coverage by testing signal strength, to gain information about an AP, and to scan an area to look for all APs regardless of SSID.
12. SVP Server Rules (Reminder) 12.1. DHCP Server Important remark: In addition to standard and common parameters (IP Address, Subnet Mask, Default Gateway IP Address, TFTP Server IP Address), the external DHCP server must be able to provide the MIPT terminal with the IP address of the SVP Server. This makes the optional DHCP fields for “Vendor Specific Options” mandatory for use with MIPT handsets.
12.2.2. SVP Server 10 and 20 Figure 44: Cascading using SVP 010 or SVP 020 A maximum of 4 SVP Servers 10 and a maximum of 2 SVP Server 20 can be cascaded in order to match the quantity of users. Only one SVP Server model can be used for cascading (SVP Server 10 or SVP Server 20 or SVP Server 100). No mixed cascading allowed. 12.2.3.
12.2.4. Self Healing SVP Functionality Figure 45: Self Healing on SVP server SVP server Self-Healing is based on the automatic election of a new Master SVP in case of Master SVP server failure (A slave SVP server becomes the Master SVP). SVP Server code 17x.035 is required to support selfhealing feature. 12.2.5. SVP server code evolution (17x.037) Reminder: For a long time Alcatel-Lucent prerequisite for SVP server code was frozen to 17x.028 code with no evolution.
12.2.6. Topology Reminder with SVP server 12.2.6.1. Non-Cascaded Mode Figure 46: SVP server Topology (non-cascaded) This topology allows VoWLAN implementation on a remote site At least one SVP is required on remote site in addition to a WLAN switch in order to avoid tromboning over the WAN. . 12.2.6.2. Cascaded Mode Figure 47: SVP server Topology (Cascaded) When SVP server capacity is not enough in terms of users, cascaded mode can be applied. Central PreSales Voice over WLAN Design Guide Rel 4.2.
13. Glossary AES Advanced Encryption Standard ALG Application Layer Gateway AP Access Point ARM Adaptative RF Management CAC Call Admission Control DFS Dynamic Frequency Selection DoS deny of Service DSCP Differentiated Services Code Point IEEE 802.
PSK Pre shared key PTT Push To Talk RAP Remote Access Point RF Radio Frequency SSID Service Set Identifier TKIP Temporal Layer Security TSpec Traffic Specifications U-APSD Unscheduled Automatic Power Save Delivery UP User Priority VLAN Virtual Local Area Network VoWLAN Voice over WLAN VRRP Virtual Router Redundancy Protocol VOC (VSM) Voice Services Module (WLAN license) WIP Wireless Intrusion Protection (WLAN license) WEP Wired equivalent Privacy WMM Wi-Fi Multi Media WPA Wi-Fi protected Access WPA2 Wi-Fi p
www.alcatel-lucent.com Central PreSales Voice over WLAN Design Guide Rel 4.2.
