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Lucent Technologies DEFINITY Enterprise Communications Server Release 8.2 Instructions Manual
Lucent Technologies DEFINITY Enterprise Communications Server Release 8.2 Instructions Manual
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DEFINITY ECS Release 8.2 Administrator’s Guide 555-233-506 Issue 1.1 June 2000 Features and technical reference 1607 Wideband Switching 20 Given this facility list concept, the algorithms have the ability to search for trunks, by facility, in an attempt to satisfy the bandwidth requirements of a given wideband call. If one facility does not have enough available bandwidth to support a given call, or it is not used for a given call due to the constraints presented in the following section, then the algorithm searches the next facility in the trunk group for the required bandwidth (if there is more than one facility in the trunk group). In addition to searching for channels based on facilities and required bandwidth, Port Network (PN) preferential trunk routing is also employed. This PN routing applies within each algorithm at a higher priority than the constraints put on the algorithm by the parameters listed later in this section. In short, all facilities that reside on the same PN as the originating endpoint are searched in an attempt to satisfy the bandwidth of a given call, prior to searching any facilities on another PN. Direction of trunk/hunting within facilities The algorithms have the ability to select trunks from low B-channel to high B-channel or from high B-channel to low B-channel with an ISDN facility. This is a per ISDN trunk group option, but infers the direction of search within all ISDN facilities (or portions of those facilities) administered within that trunk group. This is necessary so the selection of trunks are not prone to as much glare as they otherwise would be if trunks were chosen in the same direction by both user and network sides of the ISDN interface. Note that in previous DEFINITY ECS releases, the order in which trunks were selected, whether through linear or circular hunting, would always be with respect to the order in which trunks were administered within the trunk group. Now, with the support of wideband services, all trunks within an ISDN trunk group optioned for wideband are ordered based on this new “direction of trunk/hunt with facilities” parameter, and without regard to the order in which trunks are administered within the trunk group. If an ISDN trunk group is not optioned for wideband, then a cyclical trunk hunt based on the administration of trunks within the trunk group is still available. H11 When a trunk group is administered to support H11, the algorithm to satisfy a call requiring 1,536 Kbps of bandwidth uses a fixed allocation scheme. That is, the algorithm searches for an available facility using the following facility-specific channel definitions. nT1: H11 can only be carried on a facility without a D-channel being signaled in an NFAS arrangement (B-channels 1-24 are used). nE1: Although the 1,536-kbps bandwidth could be satisfied using a number of fixed starting points (for example, 1, 2, 3, etc.) the only fixed starting point being supported is 1. Hence, B-channels 1–15 and 17–25 are always used to carry an H11 call on an E1 facility.
DEFINITY ECS Release 8.2 Administrator’s Guide 555-233-506 Issue 1.1 June 2000 Features and technical reference 1608 Wideband Switching 20 If the algorithm cannot find an available facility within the trunk group that meets these constraints, then the call is blocked from using this trunk group. In this case, the call may be routed to a different trunk group preference via Generalized Route Selection (GRS), at which time, based on the wideband options administered on that trunk group, the call would be subject to another hunt algorithm (that is, either the same H11 algorithm or perhaps an N x DS0 algorithm described in a later paragraph). This same hunt algorithm, when offered any other call (other than a 1,920-kbps call) attempts to preserve idle facilities by selecting trunk(s) in a partially contaminated facility if one exists. If the bandwidth required by this call cannot be satisfied by any partially contaminated facility, then the call is placed on available trunk(s) within an idle facility, thus contaminating the facility. Again, facilities are selected via the trunk group’s facility list and with PN preference, and trunk(s) within a facility are selected based on the direction of channel search administered. Note that on a T1 facility, a D-channel is not considered a busy trunk and results in a facility with a D-channel always being partially contaminated. On an E1 facility, however, a D-channel is not considered a busy trunk because H11 and H12 calls may still be placed on that facility; an E1 facility with a D-channel and idle B-channels is considered an idle facility. H12 Since H12 is 1,920 Kbps which is comprised of 30 B-channels, a 1,920-kbps call can only be carried on an E1 facility. As with H11, the hunt algorithm uses a fixed allocation scheme with channel 1 being the fixed starting point. Hence, an H12 call always is carried on B-channels 1 to 15 and 17 to 31 on an E1 facility (as illustrated in the following table). When offered any other call (other than a 1,536-kbps call), the algorithm behaves as it does when H11 is optioned. DS0s Comprising Each Channel FacilityISDN Interface H11 H12 T1 T123B + D 24B (NFAS)- 1-24- - E1 E130B + D 31B (NFAS)1-15, 17-25 1-15, 17-251-15, 17-31 1-15, 17-31
DEFINITY ECS Release 8.2 Administrator’s Guide 555-233-506 Issue 1.1 June 2000 Features and technical reference 1609 Wideband Switching 20 H0 When a trunk group is administered to support H0, the algorithm to satisfy a call requiring 384 Kbps of bandwidth also uses a fixed allocation scheme. Unlike the H11 fixed scheme which only supports a single fixed starting point, the H0 fixed scheme supports four (T1) or five (E1) fixed starting points. The H0 algorithm searches for an available quadrant within a facility based on the direction of trunk or hunt administered. If the algorithm cannot find an available quadrant within any facility allocated to this trunk group, then the call is blocked from using this trunk group. Again, based on GRS administration, the call may route to a different trunk group preference and be subject to another algorithm based on the wideband options administered. This same trunk or hunt algorithm, when offered any narrowband or N x DS0 call, attempts to preserve idle quadrants by choosing a trunk(s) in a partially contaminated quadrant if one exists. If a partially contaminated quadrant capable of carrying the call does not exist, then the call is placed on available trunk(s) within an idle quadrant, thus contaminating the quadrant. Again, facilities are selected via the trunk group’s facility list and with PN preference, and a trunk(s) within a facility is selected based on the direction administered. Note that a D-channel is considered a busy trunk and results in the top most quadrant of a T1, B-channels 19 to 24, always being partially contaminated. This is not true for NFAS. If this H0 optioned trunk group is also administered to support H11, H12, or N x DS0, then this algorithm also attempts to preserve idle facilities. In other words, when offered a narrowband, H0, or N x DS0 call, the algorithm searches partially-contaminated facilities before it searches to idle facilities. N x DS0 For the N x DS0 multi-rate service, a trunk group parameter determines whether a floating or a flexible trunk allocation scheme is to be used. The algorithm to satisfy an N x DS0 call is either floating or flexible. nFloating (Contiguous) — In the floating scheme, an N x DS0 call is placed on a contiguous group of B-channels large enough to satisfy the requested bandwidth without any constraint being put on the starting channel (that is, no fixed starting point trunk). nFlexible — In the flexible scheme, an N x DS0 call is placed on any set of B-channels as long as the requested bandwidth is satisfied. There is absolutely no constraint such as contiguity of B-channels or fixed starting points. Of course, as with all wideband calls, all the B-channels comprising the wideband call must reside on the same ISDN facility.
DEFINITY ECS Release 8.2 Administrator’s Guide 555-233-506 Issue 1.1 June 2000 Features and technical reference 1610 Wideband Switching 20 Regardless of the allocation scheme employed, the N x DS0 algorithm, like the H11 and H12 algorithms, attempts to preserve idle facilities when offered B, H0, and N x DS0 calls. This is important so that N x DS0 calls, for large values of N, have a better chance of being satisfied by a given trunk group. However, if one of these calls cannot be satisfied by a partially-contaminated facility and an idle facility exists, a trunk on that idle facility is selected, thus contaminating that facility. There are additional factors to note regarding specific values of N and the NxDS0 service: — N = 1 — this is considered a narrowband call and is treated as any other voice or narrowband-data (B-channel) call. — N = 6 — if a trunk group is optioned for both H0 and N x DS0 service, a 384-kbps call offered to that trunk group is treated as an H0 call and the H0 constraints apply. If the H0 constraints cannot be met, then the call is blocked. — N = 24 — if a trunk group is optioned for both H11 and N x DS0 service, a 384-kbps call offered to that trunk group is treated as an H0 call and the H0 constraints apply. If the H0 constraints cannot be met, then the call is blocked. — N = 24 — if a trunk group is optioned for both H11 and N x DS0 service, a 1,536-kbps call offered to that trunk group is treated as an H11 call and the H11 trunk allocation constraints apply. — N = 30 — if a trunk group is optioned for both H12 and N x DS0 service, a 1,920-kbps call offered to that trunk group is treated as an H12 call and the H12 trunk allocation constraints apply. Glare prevention Glare occurs when both sides of an ISDN interface select the same B-channel for call initiation. For example, a user side of an interface selects the B-channel for an outgoing call and, before the switch receives and processes the SETUP message, the switch selects the same B-channel for call origination. Since wideband calls use more channels, the chances of glare are greater. Glare conditions can be limited with proper channel administration, but they may never be eliminated and some calls may still be dropped. Some glare situations might not be resolvable. In one case, the network and the user side may send SETUP messages simultaneously or nearly simultaneously. Another glare scenario can occur in the brief window after the SETUP message has been sent but before the first response is received from the switch at the other side of the interface. If an incoming SETUP arrive during this window, the incoming SETUP message is allowed to proceed and the outgoing call is dropped. Various glare situations and their resolution are described in the following table.
DEFINITY ECS Release 8.2 Administrator’s Guide 555-233-506 Issue 1.1 June 2000 Features and technical reference 1611 Wideband Switching 20 DEFINITY ECS does not negotiate channels for wideband calls. GLARE RESOLUTION Outgoing Call TypeIncoming Call TypeSwitch-Supporting User ProtocolSwitch-Supporting Network Protocol B-channel B-channel No negotiation Incoming call (from network) winsNegotiation is attempted Incoming call (from user) dropped if negotiation is unsuccessful Outgoing call (to network) retried on another trunkOutgoing call (to user) stays up B-channel(s) Wide No negotiation No negotiation Incoming call (from network) droppedIncoming call (from user) dropped Outgoing calls (to network) stay up but likely are dropped by network because channels are in use, although there is a possibility some switches might negotiate these calls.Outgoing calls (to user) stay up and possibly stay up if other side lets the network call win. Wide B-channel(s) No negotiation Negotiation is attempted Incoming call (from network) winsIncoming call (from user) dropped if negotiation is unsuccessful Outgoing call (to network) retried on another trunkOutgoing call (to user) stays up Wide Wide No negotiation No negotiation Incoming call (from network) droppedIncoming call (from user) dropped Outgoing call (to network) stays up but likely are dropped by network because channels are in use.Outgoing call (to user) stays up and may not be dropped by other side because other side, if it is not a DEFINITY ECS, may let the network call win. Continued on next page
DEFINITY ECS Release 8.2 Administrator’s Guide 555-233-506 Issue 1.1 June 2000 Features and technical reference 1612 Wideband Switching 20 To reduce glare probability, the network needs to be administered so both sides of the interface select channels from opposite ends of facilities. For example, on a 23B+D trunk group, the user side could be administered to select B-channels starting at channel 23 while the network side would be administered to start selecting at channel 1. Using the same example, if channel 22 is active but channel 23 is idle, the user side should select channel 23 for re-use. This is known as linear trunk hunt and is the hunt option used by DEFINITY ECS for wideband. Blocking prevention Blocking occurs when insufficient B-channels required to make a call are available. Narrowband calls require only one channel so blocking is less likely than with wideband calls that require multiple B-channels. Blocking also occurs for wideband calls when bandwidth is not available in the appropriate format (that is, fixed, floating, or flexible). To reduce blocking, the switch selects trunks for both wideband and narrowband calls to maximize availability of idle fixed channels for H0, H11, and H12 calls and idle floating channels for N x DS0 calls that require a contiguous bandwidth. The strategy for preserving idle channels depends on the channel type. The chances for blocking are reduced if you use a flexible algorithm, assuming it is supported on the other end. Considerations nFor example, if the user side is provisioned to start at the high side (DS0 23) and DS0 22 is idle but DS0 23 is active, reselect DS0 22 for the next call. This is known as linear trunk hunting. Only the direction of hunt is administrable. Channel Type Blocking Minimization Strategy H0 Preserve idle quadrants H11 Preserve idle facilities H12 Preserve idle facilities Flexible NxDS0 Preserve idle facilities Floating NxDS0 Preserve idle facilities as first priority
DEFINITY ECS Release 8.2 Administrator’s Guide 555-233-506 Issue 1.1 June 2000 Features and technical reference 1613 Wideband Switching 20 Interactions nAdministered Connections Provides call initiation for WAEs. All Administered Connections that originate from WAEs use the entire bandwidth administered for WAE. The destination of an Administered Connection can be a PRI endpoint. nAutomatic Circuit Assurance Treats wideband calls as single-trunk calls so that a single ACA-referral call is made if an ACA-referral call is required. The call is on the lowest B-channel associated with the wideband call. nCall Coverage A wideband endpoint extension cannot be administered as a coverage point in a call-coverage path. nCall Detail Recording When CDR is active for the trunk group, all wideband calls generate CDR records. The feature flag indicates a data call and CDR records contain bandwidth and Bearer Capability Class (BCC). nCall Forwarding You must block Call Forwarding through Class of Service. nCall Management System and Basic Call Management System Wideband calls can be carried over trunks that are measured by CMS and BCMS. Wideband endpoints are not measured by CMS and BCMS. nCall Vectoring PRI endpoints use a vector-directory number when dialing. For example, PRI endpoint 1001 dials VDN 500. VDN 500 points to Vector 1. Vector 1 can point to other PRI endpoints such as route-to 1002, or route-to 1003, or busy. Call Vectoring is used by certain applications. When an incoming wideband call hunts for an available wideband endpoint, the call can route to a VDN, that sends the call to the first available PRI endpoint. nClass of Restriction COR identifies caller and called-party privileges for PRI endpoints. Administer the COR so that account codes are not required. Forced entry of account codes is turned off for wideband endpoints. nClass of Service COS determines the class of features that a wideband endpoint can activate.
DEFINITY ECS Release 8.2 Administrator’s Guide 555-233-506 Issue 1.1 June 2000 Features and technical reference 1614 World-Class Tone Detection and Generation 20 nFacility and Non-Facility Associated Signaling FAS and NFAS with or without D-Channel Backup requires administration via signaling groups for trunk-side wideband interfaces. nFacility Busy Indication You can administer a busy-indicator button for a wideband-endpoint extension, but the button does not accurately track endpoint status. nFacility Test Calls Use Facility Test Calls to perform loop-back testing of the wideband call facility. nGeneralized Route Selection GRS supports wideband BCC to identify wideband calls. GRS searches a route pattern for a preference that has wideband BCC. Route preferences that support wideband BCC also support other BCCs to allow different call types to share the same trunk group. nCO Trunk (TTC - Japan) Circuit Pack The CO Trunk (TTC - Japan) circuit pack cannot perform wideband switching. No member of the circuit pack should be a member of a wideband group. World-Class Tone Detection and Generation World-Class Tone Detection allows DEFINITY ECS to identify and handle different types of call-progress tones. The tone detector and identification is used to display on Data Terminal Dialing and for deciding when to send digits on trunk calls through Abbreviated Dialing, ARS, AAR, and Data Terminal Dialing. World-Class Tone Generation allows you to define call-progress tones. You can select values for frequency and cadence. If you do not define a call-progress tone, DEFINITY ECS sends silence. Brief call-waiting tones are optimal because, while a tone is sounding, speech cannot be heard. A Lucent representative must administer tone detection and tone generation when establishing country-specific system parameters. Interactions nData Modules Multiline Data Terminal Dialing is disabled if the Multiple-line Level of Tone Detection field is medium or broadband. It is enabled if the Level of Tone Detection field is precise.
References 1615 Basic DEFINITY ECS documents 21 DEFINITY ECS Release 8.2 Administrator’s Guide 555-233-506 Issue 1.1 June 2000 21 References This chapter contains a list of user documents for the DEFINITY Enterprise Communications Server (ECS) Release 8.2. Most of these documents are backward compatible with DEFINITY ECS Release 7 systems. To order these or other DEFINITY documents, contact the Lucent Technologies Publications Center at the address and phone number on the back of the title page of this document. A complete catalog of Business Communications Systems (BCS) documents is available on the World Wide Web: http://www.lucent.com/enterprise/documentation Basic DEFINITY ECS documents These documents are issued for all new and upgrade DEFINITY ECS Release 8.2 systems. Administration The primary audience for these documents consists of customer administrators. DEFINITY ECS Release 8.2 — Administrator’s Guide, 555-233-506, Issue 1 A task-based document that provides step-by-step procedures for administering the switch. This book contains information previously found in DEFINITY ECS Administration and Feature Description, 555-230-522, and DEFINITY ECS Release 8 — Administrator’s Guide, 555-233-502, as well as new information for this release.
DEFINITY ECS Release 8.2 Administrator’s Guide 555-233-506 Issue 1.1 June 2000 References 1616 Basic DEFINITY ECS documents 21 DEFINITY ECS Release 8.2 — Administration for Network Connectivity, 555-233-504, Issue 1 Describes how to administer connections between DEFINITY ECS switches (csi, si, and r models) for DCS messaging. The main focus is on TCP/IP connectivity introduced with DEFINITY Releases 7 and 8, including voice over IP (VOIP). DEFINITY ECS Release 8.2 — Change Description, 555-233-411, Issue 1 Provides a high-level overview of what is new in DEFINITY ECS R8.2. Describes the hardware and software enhancements and lists the problem corrections for this release. It also includes any last-minute changes that come in after the remaining books have gone to production. DEFINITY ECS Release 8.2 — System Description, 555-233-200, Issue 1 Provides hardware descriptions, system parameters, listing of hardware required to use features, system configurations, and environmental requirements. DEFINITY System’s Little Instruction Book for basic administration, 555-233-756, Issue 1 Provides step-by-step procedures for performing basic switch administration tasks. Includes managing phones, managing features, routing outgoing calls, and enhancing system security. DEFINITY System’s Little Instruction Book for advanced administration, 555-233-757, Issue 1 Provides step-by-step procedures for managing trunks, managing hunt groups, setting up night service, writing vectors, recording announcements, using reports, and understanding call centers. DEFINITY System’s Little Instruction Book for basic diagnostics, 555-233-758, Issue 1 Provides step-by-step procedures for baselining your system, solving common problems, reading alarms and errors, using features to troubleshoot your system, and contacting Lucent.