igar

Inter-Gateway Alternate Routing Avaya Communication Manager 5.2.1 - Issue 1.0 Abstract This paper describes the Inter-Gateway Alternate Routing (IGAR) and related features, with the goal of advising sales teams and customers on when IGAR works well, and when caution should be exercised before deploying IGAR in a customer network. This paper does not provide step-by-step instructions for configuring IGAR -- for that, the reader should consult standard customer documentation. Author: CDB Reviewed: various Date: 16 Apr 2010 Systems Engineering - Basking Ridge White Paper ©2010 Avaya Inc. All Rights Reserved page 1 of 12 IGAR.mkr COMPAS 137297 and contain just enough detail to explain things clearly without overwhelming the reader with non-essential information. 3. More general information such as this can be found in customer documentation (see http://support. In the future this White Paper may be expanded to cover Dial Plan Transparency and Coverage to Remote Voice Mail. as well as customers developing a plan for routing high-quality voice calls through their corporate network.g.323 and non-IP trunks Network Status Purpose Provides QSIG feature transparency through non-QSIG (e. The following table includes a related fourth feature as well: Separation of Bearer and Signaling. public) network Provides voice connectivity via public trunks when data network cannot handle additional traffic Additional Notes Separation of Bearer and Signaling (SBS) Network is intact Similar in concept to DCS+ Inter-Gateway Alternate Routing (IGAR) Single server with multiple PNs / MGs Network is intact but has limited bandwidth Table 1: Feature Summary and Comparison 1. Customers must understand how IGAR impacts call flow and system performance before implementing IGAR in their corporate telecommunication network. Introduction Avaya Communication Manager (CM) software offers a number of features that let customers reroute their calls via the PSTN during outages in their corporate LAN or WAN. 2.Basking Ridge White Paper ©2010 Avaya Inc. These include the following: • • • Inter-Gateway Alternate Routing (IGAR) Dial Plan Transparency in Survivable Mode (DPT) Coverage to Remote Voice Mail This White Paper describes the configurations in which IGAR can be safely used. Key Message IGAR is well suited for many.com).1. but they remain out of scope for now. it is not the intent of these notes to explain feature administration and operation.mkr COMPAS 137297 . Definition of Terms Because CM servers offer several features similar to IGAR. All Rights Reserved page 2 of 12 IGAR. the three other features listed below are outside the scope of this White Paper. Note that other than being presented as a contrast to IGAR. we start by laying out when each of these features apply to a customer network.1 The intended audience includes Avaya Tier III and Tier IV technical support and design personnel.. other than the feature comparison in Section 3. Feature Server Configuration Multiple servers interconnected by H. In particular. except for aspects that may be overlooked or misunderstood.avaya. but not all. customer networks. as well as those configurations in which customers may experience trouble. Author: CDB Reviewed: various Date: 16 Apr 2010 Systems Engineering . These notes are meant to be brief enough that the reader can find what he/she needs quickly. CM server determines the direction of the trunk call. 5. All Rights Reserved page 3 of 12 IGAR. regardless of the direction of the original station-to-station call. 6.5 for events that trigger IGAR. The IGAR trunk drops when the call drops.Feature Server Configuration Network Status Purpose Additional Notes Most station features are not available. When the association is complete. special DTMF signaling (carried in-band over the trunk) lets the CM server associate the incoming trunk call with the outgoing trunk call and the original station-to-station call.1 Control Flow . the IGAR trunk call is set up in the same direction. but User B does *not* begin to ring. b.Station-to-Station Call Avaya personnel and customers often want to know the control flow of an IGAR call. 8. User A in Network Region X calls User B in Network Region Y. 2. See Section 4. 1. 7. This is not under the control of the customer. 4. so that it is now fully within NR X. The IGAR trunk stays active as long as the call stays up. The FRL and Bearer Capability (voice/data) of the endpoint on the side originating the trunk call (this may be User A or User B) is considered when selecting the preference in the route pattern. CM server determines that IGAR must be used to set up the bearer connection from A to B. The outgoing trunk must be in the same Network Region as the side originating the call (this may be NR X or NR Y). 9. with the following special cases: a. IGAR Feature Overview 4.Basking Ridge White Paper ©2010 Avaya Inc.2 3. c. CM server originates a trunk call between the two Network Regions using the administered IGAR Listed Directory Numbers and standard Automatic Route Selection (ARS). but in general. the incoming trunk must be in the same Network Region as the other side. 2. the IGAR trunk is dropped. User A hears ringback. The IGAR trunk call is answered immediately. CM begins to ring User B. Users are warned by “SV” reason code Can be used together with DPT Dial Plan Transparency (DPT) Same as IGAR Network outage has caused some PNs / MGs to disconnect from main CM server Lets users keep dialing between PNs / MGs without being aware of outage Coverage to Remote Voice Mail Same as IGAR Same as DPT Provides coverage to central voice mail server Table 1: Feature Summary and Comparison 4. Likewise. Author: CDB Reviewed: various Date: 16 Apr 2010 Systems Engineering .mkr COMPAS 137297 . Special Case: If the call is transferred from User B to a user in NR X. A hears ringback ISDN call setup signaling Trunk call answered. and IGAR is required for calls between those two Network Regions.for example. All Rights Reserved page 4 of 12 IGAR. when User A in NR X places an outgoing call over a trunk in NR Y. In Author: CDB Reviewed: various Date: 16 Apr 2010 Systems Engineering . DTMF signaling starts New Haven Call appearance on B reserved.2 Control Flow: Station-to-Trunk Call IGAR may be needed on a call from a station to a trunk -. B rings. B answers call A hangs up ISDN call clearing Call drops at B Figure 2: Possible Flow of an IGAR call 4.mkr COMPAS 137297 .Basking Ridge White Paper ©2010 Avaya Inc. B does not ring CM server originates ISDN call from New Haven DTMF signaling succeeds.Net Rgn X Hartford User A CM Server Net Rgn Y Net Rgn Y New Haven Direction of call User B Trunk Group Trunk Group Public Network Figure 1: Possible Flow of an IGAR call Hartford A calls B. the IGAR trunk call from NR X to NR Y is set up in parallel with the trunk call leaving NR Y. If sequential processing is selected.0 software will let customers force sequential processing.4 Measurements and Status Two forms can be used to verify the connection of an active call that uses IGAR for its bearer connection: 1) status trunk shows that the trunk is being used for an IGAR connection. CM software delays originating the QSIG / SIP trunk call to the Voice Mail server until the IGAR trunk between the Network Regions is active.3 A Special Case .most such cases. If User A in NR X calls a Voice Mail server using a hunt group extension.QSIG / SIP Voice Mail Calls via a QSIG or SIP trunk to a Voice Mail server are an exception. the CM server will not initiate the outgoing trunk call until the IGAR trunk connection is active. 4.Basking Ridge White Paper ©2010 Avaya Inc. Author: CDB Reviewed: various Date: 16 Apr 2010 Systems Engineering . this “parallel processing” reduces the user-visible delay on outgoing trunk calls. -------------------------------------------------------------------------------status trunk 1 TRUNK GROUP STATUS Member Port Service State Mtce Connected Ports Busy 0001/001 01A0801 out-of-service-NE no 0001/002 01A0802 out-of-service-NE no 0001/009 01A1101 in-service/active no IGAR 02A1101 S00013 S00002 0001/010 01A1102 in-service/idle no -------------------------------------------------------------------------------status trunk 1/9 Page 1 of 5 TRUNK STATUS Trunk Group/Member: 0001/009 Port: 01A1101 Signaling Group ID: 1 IGAR Connection? yes Connected Ports: IGAR 02A1101 S00013 S00002 ------------------------------------------------------------------------------Service State: in-service/active Maintenance Busy? no CA-TSC state: not allowed 3.mkr COMPAS 137297 . and the QSIG / SIP trunk dedicated to that server is in NR Y. CM6. If the two trunk calls were to be set up in parallel. In most cases.3 4. because the QSIG/ SIP Voice Mail call generally sets up very quickly. then the caller would often miss the first few words of the Voice Mail greeting. This is necessary. All Rights Reserved page 5 of 12 IGAR. Because this parallel processing can cause a brief loss of talk path at the start of the call in some cases. 55:2876/g729a/20ms S00029:RX:135.11.11.213. -------------------------------------------------------------------------------status station 8864000 Page 8 of 9 SRC PORT TO DEST PORT TALKPATH src port: S00002 S00002:TX:135.mkr COMPAS 137297 . All Rights Reserved page 6 of 12 IGAR.11.58:2924/g729a/20ms:TX:tdm:a64 02A1101:RX:tdm:a64 TX:IGAR-Trunk 01A1101:RX:IGAR-Trunk TX:tdm:a121 01A0201:RX:tdm:a121:TX:135.55:2808 15:34:37 dial 011498954752121153599999# route:ARS 15:34:37 term trunk-group 1 cid 0xba 15:34:37 dial 011498954752121153599999# route:ARS 15:34:37 route-pattern 12 preference 1 cid 0xba 15:34:37 seize trunk-group 1 member 10 cid 0xba 15:34:37 Calling Number & Name 9089539999 EXT 190895399 15:34:37 dial 011498954752121153599999# route:ARS 15:34:37 route-pattern 12 preference 1 cid 0xba 15:34:37 seize trunk-group 1 member 10 cid 0xba 15:34:37 Proceed trunk-group 1 member 10 cid 0xba 15:34:37 tone-receiver 01A0506 cid 0xba 15:34:37 Alert trunk-group 1 member 10 cid 0xba 15:34:37 active trunk-group 1 member 10 cid 0xba 15:34:37 IGAR active call app A trunks 1/10 & 2/10 cids 0xba & 0xbb 15:35:17 idle station 8864000 cid 0xb9 15:35:17 idle cid 0xba -------------------------------------------------------------------------------- Author: CDB Reviewed: various Date: 16 Apr 2010 Systems Engineering .209.Basking Ridge White Paper ©2010 Avaya Inc.105.209.209.209.58:2668 15:34:37 dial 17324314875 15:34:37 ring station 17324314875 cid 0xb9 15:34:37 IGAR starting call app A station 17324314875 cid 0xb9 15:34:37 G711MU ss:off ps:20 rn:1/1 135.143:2798 135.185.6.11.11.2) status station on either station shows that IGAR has been used to set up the bearer connection.191:3054/g729a/20ms 02A0201:RX:135.11.185.105.39:3250 135.166:2048/g729a/20ms dst port: S00029 -------------------------------------------------------------------------------- The list trace station and list trace trunk commands show whether IGAR has been invoked on a call in progress: -------------------------------------------------------------------------------LIST TRACE time data 15:34:36 active station 8864000 cid 0xb9 15:34:36 G711MU ss:off ps:20 rn:2/2 135. Dynamic CAC: The administered CAC value can be changed dynamically by all Avaya H. the gateway re-registers with the CM server using a dial-up connection. and changes the CAC limit to zero. 3. CM uses test packets to measure the quality of the customer data network. Author: CDB Reviewed: various Date: 16 Apr 2010 Systems Engineering .Basking Ridge White Paper ©2010 Avaya Inc.5 IGAR Triggers A number of events can trigger a CM server to invoke IGAR.IGAR/DPT LDN Extension Max Trks Region Name DPT? Location 1 New Jersey (PN 1) 1908-953-9999 10 n 1 2 EMEA (PN 2) 2115-359-9999 10 n 2 -------------------------------------------------------------------------------- 4. In this case.6 Delayed Ringing On a typical inter-region call. Forced IGAR: If a customer knows their data network does not have the bandwidth to carry voice calls between two Network Regions. If the thresholds administered on page 1 of the IP Options form are exceeded. 2.To get an overall view of how IGAR is being used on a daily basis. there is no “trigger” -.4 4.that is.mkr COMPAS 137297 .IGAR is used on every call between the two NRs. IGAR is triggered.248 gateways except the G700. forcing all new calls to use IGAR. from the time the destination call appearance is selected until the time 4. All Rights Reserved page 7 of 12 IGAR. the calling and called parties are not aware that IGAR has been triggered. The main impact on users is that a time gap is introduced between Step 3 and Step 7 in Section 4. Customers can also use forced IGAR temporarily to verify they have set up IGAR call routing correctly.1 -. When that occurs. 1. The calling party hears ringback. and are a static representation of how much traffic the customer expects their data network can carry with reasonable voice quality. and the called party does not ring until the IGAR trunk is active and the talk path is open and connected. Static CAC: The most commonly used trigger is a new call that exceeds Call Admission Control (CAC) limits. When network quality is restored. This typically happens when the gateway becomes disconnected from the main CM server. IGAR measurements can be viewed in the rightmost column of the status ip-network-region form: -------------------------------------------------------------------------------Inter Network Region Bandwidth Status Number of # Times Src Dst Conn Conn BW-limit BW-Used(Kbits) Connections BW-Limit IGAR Rgn Rgn Type Stat Tx Rx Tx Rx Hit Today Now/Today pass 2 Calls 0 0 0 0 0 0/ 2 Video: 0 Calls 0 0 0 0 0 Priority: 0 Calls 0 0 0 0 0 -------------------------------------------------------------------------------2 1 direct All the network regions with IGAR or DPT enabled can be viewed using the list ip-network-region igardpt report: -------------------------------------------------------------------------------IP NETWORK REGIONS . These limits appear on the IP Network Region form. 4. they can force IGAR to be used on all calls between those NRs. even if they plan to use one of the other IGAR triggers just described. IGAR stops being used for new calls. Network Measurements: If a customer enables Special Application SA9020. but none of them supports Whisper Page. when determining proper CPU occupancy. In other words.Basking Ridge White Paper ©2010 Avaya Inc. Pause = 150 msec. For example. DCS. the delayed ringing described earlier can lead to some undesirable feature interactions.that call appearance begins to ring. If users in a given Network Region expect to use IGAR frequently.on a call that triggers IGAR. the call may go to coverage even before the called party has a chance to answer the call. This lets the call cover normally in case the IGAR trunk call cannot be set up for some reason. These have two advantages: The call setup time itself is fast. Frequent IGAR invocation must also be factored into the amount of traffic a CM server can handle. Pause = 60 msec. using trunks “behind the scenes” to set up a high-quality talk path. the number of calls that are expected to trigger IGAR should be tripled to account for the outgoing and incoming trunk calls. speed up the DTMF signaling exchange (Step 6 in Section 4. By default. and SIP all support Automatic Callback between CM servers. meaning that some features should be used with care -.8 Impact of Call Setup Delay on Station Features Feature-transparency protocols like QSIG. non-ISDN) trunk group must be used.mkr COMPAS 137297 . The problem in this case can be alleviated by reducing the End-to-End Signaling timers (see Section 4. However. This can be done in a few ways: • Use “fast” trunk groups whenever possible.. reduce the timers again. or by increasing the coverage ringing interval5.g.1) by reducing the End-to-End Signaling timers on that trunk group. However. • 4.or not at all -. because every call that triggers IGAR spawns two others. Call Coverage For example. If they work. QSIG. It is advisable to do this in steps -.for example. normal call timers are running -. ISDN trunks (PRI or BRI) are good choices. During this delay. Author: CDB Reviewed: various Date: 16 Apr 2010 Systems Engineering . If a “slow” (e. let’s look at call coverage. if IGAR trunk setup delays are long. the two trunk calls also reduce the number of trunks available for “real” incoming and outgoing calls. IGAR offers users the entire set of station features. The degree to which the timers can be reduced depends on the Service Provider Network the customer uses to interconnect the Network Regions. It may not be possible to reduce them down to the 80 / 60 settings that ISDN trunks use by default. and the default End-to-End Signaling timers are short: Tone = 80 msec. the “don’t answer” interval for features such as coverage and call forwarding. It is strongly recommended that customers design their networks to keep this time gap as short as possible. 4. All Rights Reserved page 8 of 12 IGAR.reduce the timers a little bit and make test calls. If the test calls stop working. Repeat until the call setup time is acceptable.6). for a total of three calls managed by the controlling CM server: • The original inter-network-region call • An outgoing trunk call • An incoming trunk call Naturally. By contrast. limit the features a user can invoke to the very few most popular ones. Note that these default to much higher values: Tone = 350 msec. a call covers to the first coverage point after 2 rings. DCS and even SIP. increase the timers until the test calls start working again. the customer may need to order more trunks for the gateways in that Network Region from their Public Network Service Provider.7 Impact on System Performance and Capacities IGAR has a non-trivial impact on system performance and overall Busy Hour Call Capacity. Within a Network Region. and Redirect on No Answer (RONA).. Because there is no signal to the administrator that talk path is now active. so the reader should not infer that IGAR is equally suitable for use by a Call Center in countries or regions where the network performance may be less robust. Announcements A third example is recording an announcement.1 Safe Configurations for IGAR IGAR is well suited for configurations in which calls between Network Regions are either basic voice calls.mkr COMPAS 137297 .because call centers are by nature high-traffic configurations with fast response time requirements. where ISDN trunks are reliable. the first few words spoken will be lost because the talk path is not yet ready. if Joanne in Jacksonville has a bridged appearance of Pierre in Paris. or they involve no features that are adversely affected by delayed ringing or delayed talk path. Such Call Centers are taking advantage of an especially good service-provider network. alternative to IP routing of bearer channels. 5.Caution! Customers should take great care before implementing IGAR in a Call Center environment. it is best to avoid IGAR for features like this. 5. This keeps the delays introduced by IGAR small enough that these Call Centers can still function at the performance level expected by the customer. Author: CDB Reviewed: various Date: 16 Apr 2010 Systems Engineering . which means the IGAR-connected agents may not be able to perform at the same level with their colleagues who do not need an IGAR connection. a system administrator can dial the Announcement Feature Access Code. VDN of Origin Announcements. because of delays in setting up connections and higher risk of calls not being connected.. For example. Specific Call Center features susceptible to failure with IGAR include Service Observing. or for individual coverage points (Coverage Path).Bridging System designers must also evaluate carefully cases when IGAR is triggered without any “advance warning” to the CM server.Basking Ridge White Paper ©2010 Avaya Inc. a talk path delay in this case cannot be avoided. Avaya is aware of a few Call Center implementations that use IGAR in countries such as Germany. followed by the appropriate digits.. All Rights Reserved page 9 of 12 IGAR. CM software cannot start to build the IGAR trunk connection until after Pierre bridges onto Joanne’s call. Announcement Playback. agents connected via IGAR will be alerted more slowly than other agents. This caution applies equally to similar features such as No Hold Conferencing. The following text taken from that PSN summarizes the reasons for this restriction: . In addition. IGAR Configuration Recommendations 5.. relatively inexpensive. users must be trained to expect a delay before they can talk or listen. and immediately start to record an announcement. This White Paper gives the reader the background to understand the reasons behind this restriction. This is a particular concern for routing ACD calls to auto-answer agents where calls can be lost under the assumption the call has been delivered. Thus. they cannot use IGAR as an . 5. If this scenario is important for a customer. But if the announcement is stored in a distant Network Region that requires IGAR.2 Call Center Configurations -. Product Support Notice PSN002190r2 was issued in late 2008 to describe the risks in doing so. This can be done system-wide by increasing the number of rings for the Subsequent Redirection Intervals (Call Coverage/Call Forwarding System Parameters). and set up calls quickly. This can lead to a scenario where a low-privilege user can call a user in another Network Region most of the time. The Dial Plan Transparency feature. but if IGAR is triggered.0 introduces a new system parameter that lets IP trunks be selected for use by IGAR. the caller simply continues to hear ringback until he/she hangs up. This means IGAR calls cannot be routed via the public network over a SIP. Details are available in customer documentation. If all the coverage points also cannot be reached. • • • • • Author: CDB Reviewed: various Date: 16 Apr 2010 Systems Engineering . Therefore. The customer cannot use Automatic Alternate Routing (AAR) or Uniform Dial Plan (UDP)7. 7. In this case. no matter whether Joanne calls Pierre or vice versa.. Not only that. Adjusting the end-to-end signaling parameters on the appropriate trunks may be necessary -. All Rights Reserved page 10 of 12 IGAR. 9. or SBS trunk group. and Los Angeles. the customer can assign the desired public-network trunk group a lower number than the trunk group belonging to the other Network Region.Basking Ridge White Paper ©2010 Avaya Inc. most likely routing to the called party’s first coverage point. the system may have reached the maximum number of IGAR trunks assigned to one of the Network Regions involved in the call. on calls between Joanne in Jacksonville and Pierre in Paris. CM generally selects the lower-numbered trunk group for IGAR. 8. the trunk call may generally be set up always from Paris to Jacksonville.see Section 4. Feature Interactions and Limitations 6. CM6.mkr COMPAS 137297 . H. 6. ARS is always used to route the IGAR call. One exception is the case where IGAR is required to connect a calling party in one Network Region (NR) to an outgoing trunk in another NR. One way to do this is to use the Multiple Locations feature. Chicago. depending on the Network Region from which they originate. using a Trunk Access Code).6. For instances. This is because we want the call to follow the normal steps for the case the called party is not available. the calling party is normally unaware that IGAR has been triggered.2 IGAR Trunk Call Routing IGAR calls have the following routing limitations: • DTMF Tones: Because the IGAR trunk call requires an exchange of DTMF tones.1. This is a critical prerequisite for successful deployment of IGAR. For example. the call does not go through. lets customers ignore the FRL and let the calls go through. if a customer strongly prefers that IGAR trunk calls be set up in a particular direction. an IGAR trunk call to Chicago must select a New York trunk if the call comes from New York. but he/she is also generally not notified if the CM server is unable to set up the IGAR trunk call. which shares many administration fields with IGAR.6 on page 7 for details. Alternatively. Incorrect call routing is a common cause of failure.g.9 6. it is a good idea to check the Denial Event log or run “list trace” on a failing IGAR call to determine the reason for the failure.323. Multiple Locations: ARS Routing must be set up so that calls to the same IGAR Listed Directory Number (LDN) use different trunk groups. Direction: The direction of the IGAR trunk call cannot be controlled by the customer.1 on page 3. Therefore. The customer can use ARS Digit Conversion to “hop” from ARS to AAR or UDP. if a CM server has a gateway in New York.6 ARS Only: As noted in Step 5 in Section 4. This lets the customer partition users into those that can use IGAR and those that cannot. the caller hears reorder tone if the IGAR trunk call fails. Denial Events are logged if an IGAR trunk call cannot be set up. or skip ARS processing and designate a particular trunk group (e. Details on this capability will be added to this paper after the feature is generally available.8 IP Trunks: IP trunks are skipped when selecting an outgoing trunk.1 Feedback to Calling / Called Party As explained in Section 4. Facility Restriction Level (FRL): The FRL of the calling party is taken into account when selecting the outgoing route pattern preference. customers must be sure that the trunks the plan to use for IGAR can transmit these tones reliably and clearly. Instead. A new CO trunk group must be created to handle incoming IGAR calls and must route these calls to the IGAR LDN for the appropriate Network Region. Normally that extension belongs to an attendant.5 Limit on Trunk Call Setup Time Once the IGAR trunk call is routed and launched. CM software optimizes the connections among the parties on the call to reduce the number of IGAR trunks required.1) within 10 seconds. Author: CDB Reviewed: various Date: 16 Apr 2010 Systems Engineering . IGAR works well with these trunks for outgoing calls from the small branch (see Section 4. This trunk group can be used for non-IGAR outgoing calls. 6. in order for the IGAR processing described in Section 4. 6. and the call will drop. Therefore.1 on page 3 to take place.3 Call Charges and Call Detail Recording (CDR) A trunk call used for IGAR is always answered. auto-attendant. or that routes IGAR calls over secure private trunks. This can happen if the customer routes some calls over very slow public-network connections. • 6. DTMF signaling will fail. or station. the IGAR Listed Directory Numbers (LDNs) associated with the calling and called Network Region appear as the calling and called parties.6 on page 7 on how to reduce delays). The CDR record for an IGAR trunk call does not report the extension of the two endpoints involved in the call that triggered IGAR. Customers concerned about encryption should probably assign high-security users to a special network region that never triggers IGAR. or a designated station. even if the called party is not available and does not answer the call. the called party is never rung.6. Non-DID trunks must be programmed with a destination extension at which all incoming calls will ring. as well as outgoing IGAR calls. A normal voice call arriving on this trunk group will be treated as an IGAR call. If not. However.Basking Ridge White Paper ©2010 Avaya Inc. but cannot handle normal incoming calls to the branch. particularly international calls. 6.6 Usage of Non-DID Trunks for IGAR Customers with very small branches may have just a few non-DID Central Office (CO) trunks at those branches. the customer must have two loop-start CO trunk groups: • The existing CO trunk group can continue to handle normal incoming and outgoing calls. Incoming calls on this trunk group ring the designated attendant.mkr COMPAS 137297 . This must be considered when setting up IGAR in regions where outgoing calls. These extra trunks are required because incoming IGAR calls must be routed to the IGAR LDN for the local Network Region. All Rights Reserved page 11 of 12 IGAR.4 Call Transfer If a call involving IGAR trunks is transferred among different Network Regions. the far end must answer and begin DTMF signaling (Step 6 in Section 4. for IGAR to work on incoming calls into these branches the customer probably must purchase additional trunks. auto-attendant.7 Encryption A call that is encrypted when traveling through the customer’s LAN or WAN may be routed over a nonencrypted public-network trunk if IGAR is triggered. are expensive. of Avaya. All other trademarks are the property of their respective owners. All Rights Reserved Avaya and the Avaya Logo are trademarks of Avaya Inc. but are presented without express or implied warranty.©2010 Avaya Inc. The technical data provided in this White Paper are believed to be accurate and dependable. All Rights Reserved page 12 of 12 IGAR. The information provided in this White Paper is subject to change without notice.mkr COMPAS 137297 . All trademarks identified by ® and ™ are registered trademarks or trademarks.Basking Ridge White Paper ©2010 Avaya Inc. respectively. Author: CDB Reviewed: various Date: 16 Apr 2010 Systems Engineering . Inc. Users are responsible for their application of any products specified in this White Paper.