IP Exchange Product Handbook v9

PRODUCT HANDBOOK

IP EXCHANGE (UK)An IP Clearinghouse Solution from BT Wholesale

Version No: 9 of 18Date of issue: 31st December 2009Product Handbook – IP ExchangeOwner of Document: Steve SherryContact No: 07917 025050

1 OUTLINE OF THE SERVICE.................................................................................................................... 3

2 KEY FEATURES AND AVAILABILITY...................................................................................................3

3 SERVICE EXCEPTIONS............................................................................................................................ 5

4 ACCESS OPTIONS..................................................................................................................................... 6

5 QUALITY OF SERVICE............................................................................................................................. 7

6 PRICING...................................................................................................................................................... 8

7 BILLING...................................................................................................................................................... 9

7.1 CREDIT VETTING..................................................................................................................................... 97.2 BT BILLING REPORTS........................................................................................................................... 10

8 ORDERING PROCESS AND PROVISION..............................................................................................10

8.1 COMPATIBILITY TESTING....................................................................................................................... 108.2 SERVICE ESTABLISHMENT..................................................................................................................... 108.3 PORT CAPACITY AMENDMENT............................................................................................................... 118.4 NUMBER MANAGEMENT – ENUM UPDATES.........................................................................................118.5 NUMBER MANAGEMENT – CUSTOMER NUMBER RANGE HOSTING........................................................118.6 NUMBER MANAGEMENT – PORTABILITY................................................................................................118.7 NUMBER MANAGEMENT – SUB-ALLOCATION OF BT NUMBER RANGES.................................................118.8 NUMBER MANAGEMENT – UPDATES OF ESDB AND BT DIRECTORY SERVICES DATABASE (OSIS).....12

9 TECHNICAL DETAILS............................................................................................................................ 12

9.1 SECURITY OF TRANSPORT BETWEEN CP AND BT.................................................................................139.2 IP VERSION.......................................................................................................................................... 139.3 DNS..................................................................................................................................................... 139.4 SIP METHODS...................................................................................................................................... 139.5 SIP TRANSPORT................................................................................................................................... 149.6 CODECS SUPPORTED........................................................................................................................... 149.7 TRANSPORT OF FAX............................................................................................................................ 159.8 TRANSPORT OF AUDIO TONES – DTMF TONES..................................................................................159.9 EMERGENCY CALLS.............................................................................................................................. 169.10 BANDWIDTH AND CALL CONTROL......................................................................................................... 169.11 CALLING LINE IDENTITY AND PRESENTATION NUMBER SUPPORT.........................................................169.12 CLI WITHHELD...................................................................................................................................... 169.13 BEARER REARRANGEMENT.................................................................................................................... 169.14 LOUDNESS LEVELS............................................................................................................................... 169.15 LONG DURATION CALLS......................................................................................................................... 17

10 IP EXCHANGE SITES.......................................................................................................................... 17

11 FAULT HANDLING AND REPAIR.....................................................................................................17

12 SERVICE CESSATION......................................................................................................................... 18

13 COMPLAINTS HANDLING................................................................................................................. 18

14 ADDITIONAL INFORMATION...........................................................................................................18

15 Glossary of Terms.................................................................................................................................... 18


1 OUTLINE OF THE SERVICE

BT Wholesale’s IP Exchange is a product positioned to meet the growing interoperability requirements in the world of IP communications allowing Communications Providers (CPs) with differing vendor, signaling and media options to interoperate seamlessly with each other. The product also allows for the routing and connection of calls with the existing TDM based PSTN.

The IP Exchange offers competitive market rates to deliver calls originating from an IP communications providers network and will pay a settlement fee for calls terminating on that network, depending on commercial agreements.

Global IP Exchange supports:-

VoIP Gateway - Break Out - from a customer’s IP network to BT and other UK fixed PSTNs, Mobile and International

Networks. Break In – from BT and other UK fixed PSTN, Mobile and International networks to a customer’s IP

network. Clearing House - VoIP to VoIP calls between IP Exchange Customers’ IP networks including BT Retail’s

own services.

2 KEY FEATURES AND AVAILABILITY

2.1 Features Overview

The underpinning requirement related to a clearinghouse service is a widening of on-net VoIP calling attributes to users not provisioned by the same service provider. Instead of operating in a closed community, many ISPs want to offer VoIP calling whereby their users will be able to make and receive VoIP based calls with users from other ISPs. Similarly, Mobile Network Operators are wishing to interoperate with each other on a global basis as part of the GSMA’s IPX project. Plus there is a growing need for interoperability with Fixed line network on an in–country basis. In all of the above cases, the plethora of suppliers, Signalling Protocols, Systems, End User instruments (clients, handsets and devices) and the abundance of Codecs for media and the interpretation of the standards means that interoperability has and will become a key factor in the conveyance of communications in an IP World.

This has a commercial as well as a technical implication. The basic premise of IP Exchange is that it will reduce the overhead of each ISP or service provider negotiating bilateral agreements for interconnecting VoIP gateways, including end user address discovery, e.g. Carrier Registration User ENUM (CRUE).

There is not one standard for VoIP, with users making VoIP calls through different and incompatible PC clients (e.g. BT Communicator and Skype), routers/modems (e.g. Vonage and Voyager) and access methods (e.g. IPStream, LLU, cable and potentially 3G mobile). However, from a user perspective this should not be a barrier.

Provided that the VoIP service is based on SIP – albeit SIP deployments are not standard – VoIP service providers will be able to stretch their on-net privileges for users to users managed by other service providers.


2.2 Functionality and Usage Scenario

To enable VoIP on-net communities to be expanded to include other service providers, the basic construct of a BT Global IP Exchange will require interconnect capability between BTs IP Voice server(s) and those of other service providers.

In many cases, however, the VoIP service of a given Service Provider will be based on different IP Voice variants to that of BT, which will entail the BT having a transcoding capability to translate and convert VoIP call routing information.

BTW will register and maintain an operator’s numbers on the ENUM (CRUE) directory. Incoming calls from the internet to a VoIP operator’s number will be pointed to the BT SIP gateway. This places the call on to BT’s IP network, with a full range of security and value-add functions (e.g. financial settlements, transcoding, authentication, anti-spam, identity fraud protection, user-defined filters etc).

Key clearing house functions include:

Gateway/clearing house for transporting VoIP bytes Logging of call routing information: origination, termination and transit points Logging of call type information: packet-size, call period Transcoding of SIP information Metering engine for bill creation and settlement between service providers

The Global IP Exchange is more than just a termination point. It is an interoperability provider for other communications providers, offering a mixed portfolio of termination, financial services, and enhanced applications. Many clearinghouses perform the following functions:

a single point of contact for termination of telephony minutes worldwide a source for termination rates to specific destinations financial accounts management settlement of accounts between carriers


High Level Architecture

ITSPsITSPs

International IP

Carriers

International IP

Carriers IP CarriersIP Carriers

PSTNPSTN

BT Global IPExchange

BT Global IPExchange

Mobile Network

Operators

Mobile Network

Operators

Billing Routing Provision Mgt

credit risk assessment between carriers receivable processing between carriers (financial settlements) quality of service (QoS) monitoring and provisioning bandwidth and IP access provisioning

Currently PSTN operators charge each other for transport and termination of telephone calls with a guaranteed quality of connection. If we assume the business model for NGN is similar to PSTN then operators of NGN VoIP networks will need to agree commercial and technical SLAs based on ITU/ETSI recommendations for security and performance as high voice quality is an end to end function.

VoIP is susceptible to network congestion, denial of service attacks and viruses, due to the shared IP network resources employed and hence management by a reliable supplier will be essential, particularly for business applications.

3 SERVICE EXCEPTIONS

There are service exceptions involving:-

Fax calls using G.729 may operate successfully however this is not guaranteed. Short Message Service and Text Messaging are NOT supported.

Break Out Calls to:

(i) 1XX, Note: These are generally CP specific and should be dealt with by the CP within their own service domain. Calls to the Operator 100 and 123 Speaking Clock, are allowed but are charged to the CP.


Mobile network

PSTN network

Call Manager

Number translation

Management information

Billing&

Charging

CP BBV network

BT Communications clearing house

CP BBV network

Connects any-to-any

IP IP

SIP-I / BICCSS7

THE NEW WORLD OF IP EXCHANGE

(ii) 112 European Emergency Services, CPs are required to change all calls originating as 112, to 999 before passing these to IP Exchange should the 999 Access option be chosen as party of the service contract.

(iii) 118 XXX, Calls to DQ services are allowed, and are charged at a rate relevant to the DQ services plus the cost of conversion for IP Exchange.

(iv) 070 Personal Numbering Services, (can be supported but only by commercial agreement, special rates are applicable).

(v) Dial up Internet Services are NOT supported.

4 ACCESS OPTIONS

Access to IP Exchange – A range of options for connection to IP Exchange are available either with or without resilience. These include:

Access Method Connection Type Resilience OptionsOption 1 - World Wide Web (Public Internet)

Virtual Connection using existing or additional bandwidth over the Internet

Connection to more than one IP Exchange POP.

Option 2 - BT’s IP ‘Colossus’ Network

BT NetFlex (Clear Bandwidth) at over 100 PoPs in the UK

Via Separate BT NetFlex circuits or Via the Internet

Option 3 - Neutral Access Points (NAP) or Direct Access (includes optional WWW fall back routing in failure mode)

10Mb, 100Mb or 1Gb Fibre or Metallic I/F at Telehouse North, London. Requires Customer to purchase Tie or Bandwidth circuits to meet at the NAP.

Via alternative NAP at another site, or Via Separate BT NetFlex circuits or Via the Internet


Option 4 - Direct Connection (includes optional WWW fall back routing in failure mode)

Bandwidth connection to the IP Exchange PoPs in Birmingham and/or Kingston (London)

Via alternative DC connection to other IP Ex PoP, or Via alternative NAP at another site, or Via Separate BT NetFlex circuits or Via the Internet

* Notes:a. Access circuits are not included as part of the BT IP Exchange service but can be ordered separately

– please contact your Account Team.b. To ensure an acceptable customer experience for voice and video calls the customer’s service to

their end user must provide sufficient capacity at all times.c. The product will use the SIP Protocol based on supporting a range of codecs including G.711 and G.729. d. For the NAPs at Telehouse North (London), full resiliency of the backend circuits (fibres) is provided. e. All connectivity within Telehouse and the BT PoP within the building is the responsibility of the customer.

5 QUALITY OF SERVICE

The IP Exchange service is designed to deliver a reliable and resilient customer experience through the use of tried and tested components, sourced from our strategic partners in industry.

MOS (Mean Opinion Score) Probes - voice quality probes to monitor voice quality.

QoS MIS reports – a range of Management Information System reports are available.

Platform Resilience – provided for all customers - access session border controllers are deployed in resilient pairs within the same location and additional layers of resilience can be achieved by bespoke design.

Access Service Assurance – Customers have the option of gaining additional service assurance by having the access method (Internet vs Direct Access vs Direct Connection) resilient, however the access maybe back to the same Session Border Controller resilient pair or to a separate PoP.

Geographic Service Assurance – additionally Customer can elect to match their own call server resilience through a second proxy accessing a second platform resilient pair of session border controllers deployed in another geographic separate BT site.

Signalling Monitoring – The signalling interfaces within or connecting to the service will be monitored on a continual basis. This will ensure adherence to standards and agreed or contracted service responsibilities.


Bandwidth and Call Control - It is the CP’s responsibility to keep within subscribed bandwidth and the maximum number of concurrent calls allowed (this will include bandwidth consumed for ingress and egress calls).

In the case that CP delivers more traffic to a BT POP, BT’s network will return the SIP Response 503. The only exception to this rule will be for emergency calls, which will be allowed regardless of subscribed limits.

The method of access to the service and the service quality of the customer’s own IP network will also influence the end-to-end quality of the IP Exchange service.

6 PRICING

The following charges will be applicable for the service. Current prices will be provided upon request:

Pre-Ordering Compatibility testing charge – this charge will only be applicable where a customer’s call server equipment is not recognised as being compatible with the BT service and hence interoperability testing is required. This will be done prior to service establishment.

Service Establishment Provision Charge – a non-reoccurring, cost orientated provision charge to cover all initial provisioning activities and service establishment.

Port Management Charge – covers the bandwidth capacity, method of access, resilience level and management of customer capacity e.g. capacity changes, ENUM number management, data build etc. Port charges are invoiced monthly in advance and are available in the following access types:-

Public Internet (WWW) access – site resilientPublic Internet (WWW) access – Geo site resilient (customer traffic is load shared across two geographically separate sites.Direct Access via a NAP (Neutral Access Point) – site resilient only.Direct Access to POP (Point of Presence) site – site resilient only.

Customers can elect to take any combination of the above port types to provide the level of service assurance they require.

The initial Port requirement carries a 12 month contractual term.Minimum order quantity of any Port type at any site is 30 Ports.Customers must maintain a minimum Port quantity of 30 Ports (of a single access type at a single site).

Call conveyance – calls will be invoiced monthly in arrears on a pence per minute basis measured by the second and rounded up to the next second. Call rates are available as:-

UK Geographic calls – a blended rate, variable by time of day to all fixed and IP Networks. BT Only fixed and IP networks variable by time of day (where the customer has the ability to

segregate BT traffic from other network traffics), and volumes are significant. Mobile – variable by terminating network and time of day. International – variable by terminating network/destination country.

Call termination – commercial settlement will be paid for calls terminating a customer’s IP Network.

Number Porting – This is based on the nominal Regulatory pricing structure available from Openreach, however BT Wholesale apply an additional sum on to of the regulatory price to cover the increased workload in applying Number Porting changes. These will be dealt with on a Single or Multi-Line or Non-Geographic basis.


Number Sub-Allocation – there is a one off (non-reoccurring) set up charge per number sub-allocated to cover BT’s internal costs of breaking out, re-routing and sub-allocating numbers.

Number Export – No Charges are applied at this time, however BT reserve the right to charge for activities should the amount of work required increases to a point where resourcing becomes an issue.

Call Detail Records – For CPs who wish to verify their interconnect bills and for Fraud Management, CPs may wish to obtain the CDRs relevant to call made into and out of their networks via the Global IP Exchange. CDRs are filtered by our Fusionworks billing system and delivered to DEDS for collection by the CP using a secure access method. This is an optional service that is chargeable on a monthly basis. Note: this facility is currently only available to CPs who already have DEDS access.

7 BILLING

7.1 Credit Vetting

All customers will be credit vetted using the standard BTWM credit vetting process.

Credit Vet 1 is a high level check of the trading entity and its directors.

Customers will be asked to provide traffic profiles as part of the initial CRF information gathering process.

Customers will also be asked to select a ‘Barring Profile’ which limits the customer’s fraud liability by electing not to pass certain high value call types e.g. fixed fee NTS and/or all PRS calls.

The customer’s traffic patterns will be loaded into and monitored by the BTW anti fraud system Rapier.

Credit Vet 2 is based on the customer’s forecast traffic profile and call barring option selected.

Depending upon the outcome of the second credit vet Customers may be asked to provide financial surety as set out in the BTWM Credit Vetting Process. In some cases Customers may be placed on a billing periodicity less than the standard 30 days (see below).

Direct Debit is the preferred method of payment.

Pre-Payment

Pre-payment is an option for a small number of CPs wishing to use IP Exchange, CPs are asked to lodge a sum with BT that is then reduced accordingly depending on the revenues generated by the CP. Note: this is a manual process and CPs are closely monitored.

We are currently looking to automate this process to allow for additional CPs to be brought into service.

7.2 BT Billing Reports

Billing will be handled via the standard BTW Interconnect Billing process and normally invoiced on a monthly basis. Customers will normally have 30 days in which to pay the previous period’s invoice (this may vary subject to credit vetting results).

Invoices are backed up by an aggregated CDR (Call Data Record) feed which shows the volume, time of day and value of calls aggregated by call type and terminating network. The back up feed is intended to aid invoice verification and does not include details of the originating end user number.

It is assumed that the Customer has the ability to generate their own CDRs for billing their end users.

Customers will be expected to invoice BT for calls terminating on their network containing the same granularity of information as outlined above. For clarity; BT will not be providing this information to Customers.

8 ORDERING PROCESS AND PROVISION


Your Account Manager (or Sales Specialist) will be able to assist you in the ordering process in the first instance and will have the necessary Contractual documentation, and Customer Requirements Form (CRF) to gather your requirements.

A Technical Account Manager (TAM) will be appointed to support the Customer through contract signature and where necessary any Compatibility Testing and associated provision activity.

8.1 Compatibility Testing

To ensure that the Customers equipment and software version are fully compatible with the BT IP Exchange platform, a degree of interoperability testing will be necessary. The length of the testing cycle is dependant upon a number of factors including the services to be used and the availability of Customer test engineers etc.

Once a signed contract has been received by the BT ACCOUNT MANAGER, the TAM will book the next available test slot and communicate this ‘time window’ to the Customer. The TAM may also ask for a re-testing questionnaire to be completed, which usually helps to reduce the number and complexity of tests required.

The TAM will also manage the customer’s numbering requirements as specified on the initial CRF. Any data build work in the PSTN must follow a regulated DMA (Data Management Amendment) process and takes not less than 30 working days to complete. Should a Customer’s numbering requirements be complex a ‘Complex DMA may be required which has a longer lead time of not less than 75 working days. The TAM will advise which type of DMA will be required.

The TAM will also manage any 999 service establishment aspects of a Customer requirement and advise on processes to update a Customer’s end user details onto the BT ESDB (Emergency services Data Base).

Once a Customer has successfully completed Compatibility Testing, the TAM (Technical Account Manager) will hand over the CRF to the IP Exchange Customer service Centre Team in Wolverhampton who will manage Service Establishment. The TAM will advise the Customer of the likely timescale for Service Establishment and the ‘live’ SIP address that should be loaded onto the Customers equipment.

8.2 Service Establishment

The IP Exchange Customer Service Team in Wolverhampton can be contacted on 0800 077 8247 opt 1.

The Customer Service Team will manage all remaining aspects of Service Establishment, Port capacity provision, loading data on ENUM, any Number Ports one in-service and the live platform and open billing accounts.

The Customer will be contacted by our engineers once Service Establishment work has been completed and asked to send some test calls to confirm settings on both the Global IP Exchange Platform and the Customers equipment have been provisioned correctly and calls can be passed.

On completion of Service Establishment the Customer Service Team will advise the Customer by email and receive a Welcome Letter, Customer Service Plan and Product Handbook.

8.3 Port Capacity Amendment

Amendment to a Customer’s Port Capacity is achieved by submitting an ‘Modify Data’ CRF (Customer requirements Form) clearly stating the additional Port type and capacity required. The minimum order increment or decrement capacity is 30 Ports but any number above this minimum is acceptable i.e. 35 Ports. In addition BT will provide a ‘buffer’ of 10% additional Port capacity free of charge to facilitate seamless growth. A further 5% of the bandwidth ordered will be reserved for 999 services, which will not be available for normal calls, however 999 calls can consume any or all of the 115% of bandwidth ordered. Version No: 9 of 18Date of issue: 31st December 2009Product Handbook – IP ExchangeOwner of Document: Steve SherryContact No: 07917 025050

The CRF should be emailed to the Customer Service Centre who will arrange provisioning / cessation activity and liaise with the Customer’s TAM as necessary.

8.4 Number Management – ENUM Updates

As a Customer either obtains new telephone numbers through, OfCom allocation (see 9.5), or BT Sub-Allocation (see 9.7) they will need to update the IP Exchange ENUM routing data base. The Customer should submit a ‘Modify Data’ CRF completing the spreadsheet in section 5 and entering instructions in section 6.

The CRF should be emailed to the Customer Service Centre who will arrange provisioning / cessation activity and liaise with the Customer’s TAM as necessary.

It is the Customer’s responsibility to ensure that the BT IP Exchange Customer Service Centre are provided with timely updates of Numbering changes (additions and losses) to ensure service levels are maintained.

8.5 Number Management – Customer Number Range Hosting

BT IP Exchange can host numbers allocated to Customers and any new number blocks obtained from OfCom should be notified to the TAM for inclusion in contract and built into ENUM as described above in section 9.4.

8.6 Number Management – Portability

Please refer to the Number Portability Handbook.http://www.btwholesale.com/pages/static/Products/Interconnect/IP_exchange.html

8.7 Number Management – Sub-Allocation of BT Number ranges

BT has geographic numbers allocated to IP Exchange for sub-allocation to Customers to support their service. Customers should contact their TAM (Technical Account Manager) who will arrange for the numbers to be sub-allocated. There is a one off set up charge per number (see section 7) which will be billed to the customer periodically. A full list of Number Ranges available is available at http://www.btwholesale.com/pages/static/Products/Interconnect/IP_exchange.html

Please refer to the Number Sub-Allocation Handbook.http://www.btwholesale.com/pages/static/Products/Interconnect/IP_exchange.html

8.8 Number Management – Updates of Emergency Services Database (ESDB) and BT Directory Services Database (OSIS)

As part of the Number Import and Sub-allocation processes, the numbers involved effectively become BT numbers as they come under BT’s CUPID ID (001), because of this BT will be the only organisation allowed to manage these numbers in relation to updating the Emergency Services Database and The BT Directory Services Database (OSIS). For these numbers CPs who request the importing of numbers or who allocate IP Exchange Sub-Allocated numbers to their end users MUST provide the IP Exchange Porting Desk with the

NUMBER, NAME, ADDRESS, POSTCODE

For each number.


http://www.btwholesale.com/pages/static/Products/Interconnect/IP_exchange.html



For all other numbers i.e. those numbers allocated to a CP by Ofcom i.e. the CP is the Range Holder, the CP MUST update the Emergency Service Database (ESDB) and Operator Services Information System (OSIS) themselves using Standard File Format arrangements.

Details on how to gain access to the ESDB are given in the embedded documents.

Details on 999 Updating Via Telesto

Details on Standard File Format

For OSIS the Information relating to gaining access can be found at:

http://www.btwholesale.com/pages/static/Products/Managed_Services_and_Outsourcing/Directory_Solutions/directory_solutions.html

9 TECHNICAL DETAILS

This document covers the interface between BT’s call server and the CP’s call server. It is assumed that only SIP will be supported for the signalling between the two carriers. H.323 and SIP-I are out of scope of the service offering.

The following types of calls will be supported across this interface: Voice calls to PSTN destinations (UK and International) Voice over IP and Video over IP will also be supported where the origination and the destination

are both on the BT Clearing House network. Emergency calls for only UK originated calls with prior agreement Service calls with prior agreement

For a CP to access the BT IP Exchange service, the CP should be able to support the following:

A SIP proxy to interface to BT’s network over the internet. In addition, it is recommended that the CP provides secure access to their network by means of

a Firewall or a Session Border Controller.

Access to the BT IP Exchange network is provided across the internet. This can be provided by BT with the following options:

Changes to routing configuration and tunnelling of traffic from the CPs network across the Internet to the IP Exchange system

Internet access (BT Net Access)

Shortly after the initial




Leased line access (High bandwidth services) to provide access direct to a VMP Node (Manchester, Birmingham, Reading, London, Croydon plus Telehouse North in London and Manchester Telecity).

Via a Network Access Point (NAP), these will be deployed across the country at major cities and towns to allow for a more cost effective solution.

9.1 Security of transport between CP and BT

In order to provide secure access from the CP’s network into the BT network, basic security will be provided by means of a firewall. The CP will need to define the signalling, media IP and MAC addresses which will be used for this service. BT will not respond to any signalling and/or media from addresses which have not been pre-agreed. Unknown MAC address will be alerted to our Platform Management centre for investigation.

BT will only send signalling and media from defined IP addresses.

9.2 IP Version

IP version 4.0 is supported.

IP Version 6.0 is not supported

9.3 DNS

In terms of the CP interaction with BT’s network, DNS capability, including SRV and A record look up, will not be supported.

9.4 SIP Methods

The supported SIP methods are detailed below.

Method SupportedInvite YesAck YesBye YesCancel YesPrack ÝesOptions YesInfo Partial (See section 3.4.8)Update Yes REFER No3xx diversions No

9.5 SIP transport

RFC 3261 allows SIP requests to be sent using reliable or unreliable protocols: UDP, TCP, or SCTP.

For this service, the following SIP signalling message transport methods will be supported: UDP TCP

The following SIP message transport methods will not be supported at present: TLS SCTP IPSEC


The SIP signalling between the CP and the BT proxy will be based on the following IETF RFCs: IETF RFC 3261, "SIP: Session Initiation Protocol" IETF RFC 3262, "Reliability of Provisional Responses in SIP" IETF RFC 3264, “An Offer / Answer Model with SDP” IETF RFC 3325, “Private Extensions to SIP for Asserted Identity within trusted networks” IETF RFC 2976, “The SIP INFO Method”

9.6 Codecs Supported

1.1.1 Between CP’s on the Clearing House

The following Voice codecs are supported for calls between CPs hosted on IP Exchange: G.711 A law (20 msec packet size) G.711 uLaw (20 msec packet size) G.729 (30 or 20 msec packet size) G.729 annex A (30 or 20 msec packet size) G.729 annex B (30 or 20 msec packet size) G.722 G.723.1 (6.3 Kbps) (30 msec packet size) G.723.1 (5.3 Kbps) (30 msec packet size) G.728 (16 Kbps) (30 msec packet size) G.726 (16 Kbps) G.726 (24 Kbps) DVI4 iLBC Speex GSM G.722.2 AMR WB DTMF Transport as for RFC 2833 DTMF transport as for SIP Info (RFC 2976) T.38 fax H.263 – for video H.264 - MPEG4 – for video

1.1.2 Between the CP and The BT PSTN

The following Voice codecs are supported:

G.711 Alaw (20 msec packet size) – European standard G.711 µlaw (20 msec packet size) – USA standard G.729 (30 msec packet size) supported by interworking with G.729a G.729 annex A (30 msec packet size) G.729 annex B (30 msec packet size) supported by interworking with G.729ab1

G.729, annex A, annex B (30msec packet size) 1

DTMF transport as for RFC2833 DTMF transport as for SIP Info (RFC 2976) – only supported in the direction from CP to PSTN. G.711 Alaw in-band fax

Inter-working of the different DTMF transport methods will not be supported.

1Annex B (silence suppression) requires that the client produces periodic media in the absence of other speech etc. to prevent the call from being terminated by media-loss timers. RTP-keepalives or RTCP packets should therefore be sent at least every 119 seconds to avoid any risk of calls dropping out.


The preferred DTMF transport method is RFC 2833.

IP Exchange will police the codecs stream bandwidth and this will be based on the packet size specified. If a CP exceeds the bandwidth for a specific codec, RTP packets will be discarded and this will result in poor voice quality.

Ptime can be used to negotiate a different packet size to that indicated above, for example to run G.729a at 20ms. However, if the reduction in packet size caused by end-user ptime negotiation results in bandwidth requirements in excess of what the platform is designed for (for example G.711 10ms) then this will result in very poor voice quality for which BT will not be held responsible.

9.7 Transport of FAX

FAX and Modem transport in band using G.711 Alaw codec is supported.

In the future, the following two additional methods will be supported to transport FAX tones:• In band with codec up-speed to G.711• T.38 transport after initial in band transfer of the Send Call Tone (CNG).

If the far end CP does not support the method of transport of the tones, the IP Exchange platform will not perform any form of inter-working between the two different methods.

9.8 Transport of audio tones – DTMF TONES

The following methods will be supported to transport DTMF tones:

In band (G.711 codec is preferred. With G.729 detection of the tones at the far end will not always be guaranteed)

RFC2833 is the preferred method for the transport of DTMF tones. Support of RFC 2833 is dependent on successful codec negotiation and requires the payload type 101 to be assigned.

SIP Info is only supported in the direction from CP to IP Exchange, where the call terminates on the PSTN.

For a CP-CP call, if the called CP does not support the method of transport of the tones, BT will not perform any form of inter-working between the two different methods.

9.9 Emergency Calls

Emergency calls from a CP will require the SIP ReqURI header to contain the emergency number (999, 112 & 18000) suffixed with the agreed CP’s Interconnect Identifier (ii) digits prior to sending to IP Exchange.

9.10 Bandwidth and Call Control

It is the CP’s responsibility to keep within subscribed bandwidth and the maximum number of concurrent calls allowed (this will include bandwidth consumed for ingress and egress calls).

BT will provide an additional 10% allowance on the ports and bandwidth ordered.

In the case that CP delivers more traffic to a BT POP, BT’s network will return the SIP Response 503. The only exception to this rule will be for emergency calls, which will be allowed subject to pre-assigned emergency call capacity being available.

9.11 Calling Line Identity and Presentation Number Support

IP Exchange supports both Network and Presentation CLIs.


For calls from the CP to IP Exchange, where the call terminates on the PSTN, the SIP FROM field is mapped to the presentation CLI while the SIP P-Asserted-ID is mapped to the network CLI. The behaviour is based on NICC document ND1017 (Table 7B), which specifies the mapping is from SIP (FROM field) to ISUP (presentation number).

For calls from the PSTN to the CP via IP Exchange, the SIP FROM field and the P-Asserted-ID field will contain the presentation number when available. If only the network number is available then this will be mapped to the SIP FROM field and the P-Asserted-ID field.

9.12 CLI Withheld

CLI restriction should be implemented as follows:

For calls from the CP to IP exchange, the CP will indicate that CLI is not for CLI display purposes by use of:

RFC3261 Section 8.1.1.3 and 20.20 which describes the use of an "Anonymous" display field to the From: header to indicate that the client is requesting privacy.

SIP Privacy Header which is described by RFC 3323.

For calls from IP Exchange to the CP, the CP is required to implement both methods of CLI restriction: RFC3261 Section 8.1.1.3 and 20.20. SIP Privacy Header which is described by RFC 3323. Note that for both methods, the Restricted

CLI should not be made available to the Called Party CPE.

9.13 Bearer rearrangement

As a result of call transfer by means of Re-INVITES, CP sometimes request rearrangement of bearers associated with the calls. Where a CP wishes to rearrange bearers to connect two call legs together, it is preferred that this is be carried out in the CPs own network.

9.14 Loudness Levels

The CP shall comply with the loudness standards ETSI TBR 8, and the CP's CPE must be able to support the following loudness rating for calls to/from IP Exchange: SLR=7dB, RLR=3dB where SLR is the sending loudness rating and RLR is the receive loudness rating

9.15 Long duration calls

Calls that have been in progress for a period greater than 4 hours are no longer released, this was a initiated following requests from several CPs, who have end users that required long calls as part of business practices. Note: CPs should be aware that this may make them vulnerable to end user activities that may result in excessive call charges, it is the CPs responsibility to make sure that they can detect these activities, so that they can control any charges that will be levied as a result of calls passing through IP Exchange.

10 IP EXCHANGE SITES

BT POPSBirmingham PoP*BT VoIP PoPGround floor Telephone House104 Newhall Street

Kingston PoP*BT2nd Floor IP POPKingston SSC Taverner House

Manchester PoP*BT 1st Floor POP roomDial House21 Chapel Street

Reading POP*BT VoIP PoPReading ZSCReading, Berkshire

Baynard PoPBTBaynard House 135 Queen Victoria Street


Birmingham B3 1BA

Birkenhead Avenue Kingston Upon ThamesKT2 6RX

SalfordManchester M3 7BA

RG2 0EW London EC4V 4AA

*Please check direct-access availability at the POP with your Technical Account Manager.

Neutral Access PointBTIS room,London Docklands North Building, Coriander Avenue, London E14 2AA

(The East building is on the same street, but BT’s main presence is in the North building)

Access to London Telehouse North

Access to the BTIS room in Telehouse north must be arranged and authorised in advance. Cabling into the BTIS room can be via approved Telehouse personnel, or a third-party supplier. The latter must be overseen by BT personnel. Physically connecting the cable to the IP Exchange equipment in Telehouse will be done by BT personnel.

The BT Technical Account Manager will be able to advise on the logistics of connecting to IP Exchange.

11FAULT HANDLING AND REPAIR

Customers can report faults 24/7 throughout the year to the IP Exchange Customer Service Team on 0800 077 8247 option 1 (also works from outside of the UK). The repair service desk will ensure that the customer has proven the fault away from their network before accepting the fault and then allocate a unique service identifier.

Repair handling teams will check IRAMS for known platform problems, record the fault instance on SPACER-R and inform operations of the problems and request a resolution, SPACE-R will be updated and the customer notified of the service restoration on completion.

12SERVICE CESSATION

Customers can cease their entire service with IP Exchange by submitting a ‘cessation’ CRF reducing their port capacity to zero. Customers need to give a minimum of 30 working days notice to facilitate re-routing activity in the PSTN etc.

13COMPLAINTS HANDLING

Any complaint regarding the IP Exchange service should in the first instance be directed to the helpdesk for resolution on 0800 077 8247 Option 2. Should a customer remain dissatisfied they should follow the escalation procedure detailed in the CSP (Customer Service Plan).

14ADDITIONAL INFORMATION

IP Exchange is not a PSTN emulation services and customers should be aware that some PSTN features that are supported by ISUP signalling are not available with this product e.g. Ring Back when Free, Malicious Call Trace etc.

The following documentation is available from your BT Account team:-


Product Handbook Number Portability Handbook Number Sub-Allocation Handbook Pre-Test Description Technical Service Description Customer Service Plan (CSP) Customer Requirements Form Contract

15GLOSSARY OF TERMS

21CN 21st Century NetworkAMR Adaptive Multi-Rate speech encodingBTWM BT Wholesale MarketsCM Commercial ManagerCNG Comfort Noise GeneratorCP Communications ProviderCRUE Carrier Registrations in User ENUMDMA Data Management AmendmentDNS Domain Name ServerDSL Digital Subscriber LineDTMF Dual Tones Multi FrequencyENUM E-164 Number MappingGSM Global System for MobileIETF Internet Engineering Task ForceIMS Internet & Multimedia ServicesIP Internet ProtocolIPSec IP Security protocolITU International Telecommunications UnionLLU Local Loop UnbundlingNGN Next Generation NetworkPOLO Payment to Other Licensed OperatorPOP Point Of PresencePSTN Public Switched Telephone NetworkQoS Quality of ServiceRFC Request for CommentRTP Real Time ProtocolSIP Session Initiation ProtocolSIP-I Session Initiation Protocol - InterconnectSCTP Stream Control Transmission ProtocolSLA Service Level AgreementSRV Service Record ValueTAM Technical Account ManagerTCP Transmission Control ProtocolTDM Time Division MultiplexingTLS Transport Layer SecurityTNO Telecommunications Network OperatorUDP User Datagram ProtocolURI Universal Resource IndicatorVoIP Voice over the Internet Protocol


IP Exchange Product Handbook v9

Documents

Transcript of IP Exchange Product Handbook v9