NGA Voice - Chorus Voice whitepaper... · PDF fileVersion '130820142432', printed from voice on November 03 2016. Voice – Access Virtual Private Line (Voice-AVPL)

Version '130820142432', printed from https://customer.chorus.co.nz/ngavoice on November 03 2016.

NGA Voice

NGA Voice Solution

Next Generation Access (NGA) Voice is a simple yet flexible layer 2 Gigabit Passive Optical Network

(GPON) solution that provides Retail Service Providers (Service Providers) with the ability to combine a

Session Imitation Protocol (SIP) based Voice solution with their NGA-based offerings.

NGA Voice Components

NGA is made up of the key components:

Optical Network Terminal

Analogue Telephone Adaptor

Voice

Point of Interconnect

Coverage Area

Handover Connection

Optical Network Terminal (ONT)

The ONT terminates the GPON services in the End User premises and provides the End User NGA

interfaces.

The standard ONT includes four ethernet UNIs and two NGA Voice ports.

Analogue Telephone Adaptor (ATA)

The ATA is an RJ11 port on the ONT that provides an analogue interface for voice.

Each ATA supports one Voice-AVPL.

The Service Provider can configure features of the ATA through TR-069 to a SIP User Agent associated to

the ATA port.


Voice – Access Virtual Private Line (Voice-AVPL)

A Voice-AVPL is an Operator Virtual Circuit between a SIP User Agent at the ONT and an E-NNI at the

Handover Connection, with the following characteristics:

Voice is encoded/decoded at a SIP User Agent on the ONT using a G.711a/μ codec at 10ms

sampling rate;

Delivered as a single VLAN (S-VID/C-VID) at the E-NNI per User Agent;

One SIP User Agent per ATA; and

Traffic is delivered using High Priority Class of Service.

Point of Interconnect (POI)

A POI is one or more Ethernet Aggregation Switches (EASs) where all traffic within that Coverage Ar ea is

aggregated for handover. A Service Provider will require a Handover Connection to receive or send traffic

to End Users within the Coverage Area.

Coverage Area

A Coverage Area is a defined geographical area comprising of a number of Access Nodes conn ected to a

POI.

Larger Coverage Areas support dual POIs where a Handover Connection in either POI can receive traffic

from all users within that Coverage Area.

Handover Connection

The Handover Link is a 1 GigE or 10 GigE interface between Chorus‟ and the Retail Service Provider‟s

network that performs the External Network to Network Interface (E-NNI) function for NGA.

Handover Connections can use Local Aggregation Grouping to provide additional throughput and/or

availability.

To use NGA the Service Provider must have the capability to access and interconnect with the service as

described in Introduction to NGA.

Service Provider Point of Presence (PoP)

NGA Voice requires interaction with Service Provider functions to operate as follows:

Fulfil

The Fulfil process is required to provision the service.

DHCP Server

The Retail Service Provider assigns the IP address of the SIP User Agent using DHCP and sets up

connectivity to the Auto Configuration Server (ACS).

ACS

The ACS configures the SIP User Agent using TR-069.

SIP Soft Switch

The Session Initiation Protocol (SIP) Soft Switch is responsible for controlling and managing VoIP calls

from and to NGA Voice connections.

Variants of NGA Voice

NGA Voice is included with baseband and thus is offered with all NGA reference offers as shown below:


NGA Evolve and NGA Business templates include one NGA Voice component with each offer. However it

is optional for Retail Service Providers to activate the voice service.

Custom NGA Offers

RSPs can request NGA Voice as part of a non-reference template using the Chorus Co-Innovation

process.

See the Chorus Co-Innovation Guide and Handbook for more information.

Geographic Availability

NGA is available where Chorus has GPON coverage. See the Bitstream Operations Manual for more

information.

NGA Voice is not offered over non-GPON Rural Broadband Initiative (RBI) Services:

NGA Business –eDMR

NGA Business – Point to Point

Relationship with other products

NGA Voice can be combined with a number of Chorus input products as shown in the figure below.


NGA Voice can share a UFB Handover Connection with NGA Evolve and NGA Business or be on a separate

Handover Connection. It cannot be delivered over an HSNS or Shared Handover Connection.


Technical Description

Network Topology

The NGA Voice service is provided by the following key capabilities:

1. ATA: The analogue Terminal Adapter (ATA) provides the ability for End Users to use analogue

telephones and telephony services on a GPON-based Bitstream access. Specifically, it converts an

analogue PSTN-compatible 2-wire voice band call into a Bitstream at the ONT, and converts a

Bitstream received from the Service Provider into an analogue PSTN-compatible 2-wire voice band call

at the ONT.

2. The Voice-AVPL service: The Voice-AVPL (Access Virtual Private Line) service provides the

underlying connectivity for carrying the VoIP packets between the ATA port on the ONT and the

'External Network to Network Interface' (E-NNI) port where the Service Provider interconnects with the

service.

3. SIP User Agent: The SIP User Agent interacts with the Service Provider soft switch to manage the ATA

Port‟s voice functions. It is configured using TR-069 and interacts with the softswitch using Session

Imitation Protocol (SIP).

The SIP User Agents in the ONT are configured via a Service Provider TR-069 Auto Configuration Servern

(ACS).

The ONT will operate:

As a dual SIP User Agent (UA), where each UA controls one of the two ATA ports.

Both SIP User Agents, if purchased, must belong to the same Service Provider;

With user specific Voice parameters configured via TR-069 / TR-104;

Both SIP User Agent operate in loosely coupled SIP mode;

A VLAN for each SIP User Agents;

Layer 3 and above networking, addressing, and provisioning provided by the Service Provider.

Physical Design

There is one RJ-11 Port per NGA Voice service for the connection of an analogue POTS device on the

ONT. The customer may wire into their premises as desired.

The ONT will connect to the GPON (Gigabit Passive Optical Network) service with a single optical Uplink

connection

The Voice traffic will be carried over the PON (Passive Optical Network) on the ONT optical uplink

There will be an External Network to Network Interface (E-NNI) at the POI. This E-NNI can be carrying

the traffic for several ATAs and other NGA services.

The POI supports a coverage area of the Chorus network, and hence a Service Provider willrequire

multiple E-NNIs if they offer service in different coverage areas.

Unique Service Identifiers

The standard ONT has two ATA Ports, each of which can support a single NGA Voice instance, as follows:


Each instance of the NGA voice service will be identified by a Chorus Access Service Identifier (ASID) in the

format of:

CHORUSNNNNNNNNNNATA1;

CHORUSNNNNNNNNNNATA2; or

CHORUSNNNNNNNNNN.

Where:

NNNNNNNNN is the ASID returned in the OO&T request for the offer;

ATA1 will be connected to port 1 of the ONT;

ATA2 will be connected to port 2 of the ONT.

CHORUSNNNNNNNNNN is used where there is only one NGA Voice service per ONT.

This unique identifier will be inserted into the DHCP Option 82 request as part of IP establishment.

In December 2013 Chorus is introducing a new Self Service Portal (SSP). Following this SSP introduction

each instance will have a unique Service Identifier. The format and notification of this ID will be advised as

part of the SSP dialogue and onboarding.

Telephony Features

The following features are supported on NGA Voice:

Two analogue RJ11C ports (one per service instance)

QOS support using High Priority class for ethernet transport

SIP signalling with RTP stream

2-Wire FXS Analogue Lines

G.711A, G.711U, 10ms or 20ms packetisation

NZ PSTN Tones and Ringing Cadences

TN12 complex impedance support

Voice Features

Incoming & Outgoing Calls

Calling Line Identification Presentation (CLIP)

Calling Line Identification Restriction (CLIR)

Message Waiting Indication (MWI)

Visual Indicator

Audible Stutter tone

DTMF in-band or RFC2833

Hot Line Immediate - Direct-URI is not supported by TR 104 so will use a proprietary TR-104

parameter.

Call Waiting

Three way calling (always enabled)

Call transfer

Call hold (always enabled)

Voice-band data using G.711A clear channel

Fax up to 9.6 kbps

Modem up to 14.4 kbps]

TTY support


G.168 echo cancellation.

Dial plan up to 1024 characters

TR-069 support to allow Service Provider‟s ACS to provision and configure the SIP User Agent.

Support for TR-104 data model format for telephony parameter configuration.

TR-098 support to provide new ACS parameters and credentials to the SIP User Agent.

Notes:

Call Forward and diversion to voicemail are Soft-Switch features, and do not require validation on the

ONT itself.

Loosely Coupled refers to the mechanism whereby features such as 3-way calling and call waiting can

be supported entirely by the endpoint without the need to interact with the Network, aside from the

requirement that this generally also needs the soft-switch to allow two voice paths to the ATA per Voice

port. The NGA Voice Service only operates in this mode.

NGA Voice Parameters

SIP User Agent Voice-related parameters will be provisioned by the Service Provider via TR-104 data

model/parameters and TR-069 protocol. The mapping table below describes how XML parameters map to

TR-104 in general:

VoIP generic parameters as per TNZ TNA 102 are pre-loaded (tones, ringing, levels, etc)

Hardware-specific parameters are pre-loaded.

Client- specific are configured by TR-104 (Softswitch address/port, digit map, digit collection timers,

rfc2833 mode)

Subscriber-data elements are configured by TR-104 (sip credentials, service assignments)

Details on the parameters and default values are documented in the NGA Voice Technical User Guide.

NGA Voice Network conditions

Voice will be carried as a unique VLAN (Voice-AVPL) from the ONT through to the Handover (E-NNI). To

support voice traffic (media and signalling), a Voice-AVPL will be configured per ONT with the following

characteristics:

300kbits/s CIR symmetrical at layer 2,

CIR=PIR

All traffic will be marked as High Priority traffic, i.e. PCP = 4; including DHCP, and DNS.

Note that Right Performing enhancements are looking at changing the PCP to 5.


Coverage Area Mapping

Mapping tables must be pre-established for NGA Voice before these services are consumed.

These tables list one Handover Connection per Coverage Area that all NGA Voice tails will be delivered to.

The bandwidth of this Handover Connection can be expanded using LAG.

NGA Evolve (E-AVPL) and NGA Voice have different mapping tables but can share Handover Connections.

Future of mapping

Mapping tables are an initial requirement for NGA voice as part of the first -in service. However Chorus is

planning to change this approach in late 2013 to be considerably more flexible and allow mapping per

Service Instance. It will still be possible to have a default handover for a coverage area.

Class of Service Specification

NGA Voice is delivered using High Priority traffic class which has been designed to the following

performance specification:

NGA Voice bandwidth is independent of E-AVPL or E-APL bandwidth, i.e. if an End User has an Evolve 1

connection with 2.5/2.5 Mbps of High Priority bandwidth on the E-AVPL then this bandwidth would not be

reduced when the End User makes a call on the NGA Voice service.

Performance is from SIP User Agent to E-NNI but excluding encoding delays;

Calculated over a 5 minute interval with a 99% compliance criterion.

Excludes frames that are submitted outside the NGA Voice traffic profile;

Note that it is not possible to explicitly measure the Layer 2 performance from a SIP User Agent.

Logical Service Design

The NGA Voice service is a 1:1 VLAN service construct between the Service Provider handover and the

end-user, i.e. all traffic must traverse the E-NNI.

The key service definitions are as follows:

NGA Voice services are defined as having a single High-Priority Class-of-Service (PCP=4) for both

signalling and media traffic.

At the E-NNI, there will be a single unique SVLAN:CVLAN per SIP User Agent (NGA Voice

instance), as determined by Chorus

As per G984, downstream Voice on the PON towards the ONT is AES encrypted. There is no

upstream encryption.

The NGA Voice Service has an MTU of 1518bytes at the ONT including CVLAN, or 1522bytes at

the Handover including S and C VLAN. (equivalent to 1514 byte untagged Ethernet frames)

The Service Provider is responsible for providing the DHCP, and DNS services for the SIP User

Agent. The TR-156 Remote ID (see Unique Service IDs above) and TR-156 Circuit ID will always be

inserted into Option 82 and can be used as a non-repudiated credential, i.e. validate the ONT trying to

connect to their network.

It is recommended that the Remote ID is used as this ID is more operationally stable.

PSTN Equivalence

The default configuration of NGA Voice is to use a G.711 A-law codec with 10ms packetisation which is

designed to provide an End User with a PSTN equivalent service in most common scenarios.

A PSTN service may carry telephony data services such as dialup modems, fax machines, Eftpos, set-top

boxes (with PSTN authentication), TTY and security/medial alarms. Since the compatibility of these devices

is dependent on the end to end Voice solution provided by the Service Provider, it is the responsibility of

the Service Provider to test what devices they will support.

Note that End Users may not be aware that some of their existing devices rely on a PSTN service.


For incoming calls NGA Voice will use the codec and packetisation interval offered in the INVITE for both

transmit and receive packetisation level, This may be different than the default and thus provide a different

experience.

The recommended default codec configuration, G.711 A-law codec with 10ms packetisation, is designed

to provide a local call Voice Quality (G.107) of 80-93.

Security

When connecting the ONT to the PON, Chorus will use a unique identification between the ONT and the

OLT that allows that ONT to only connect to the desired PON. If the ONT is moved around it will not be

able to operate, as it will not be authenticated by the OLT.

Each Voice-AVPL provides a separate distinct point-to-point virtual ethernet network between the ONT

SIP User Agent and the E-NNI and delivered as a unique svid/cvid vlan at the handover connection. This

prevents communication between ONTs or devices, i.e. all traffic from an NGA Voice service will need to

traverse the Service Provider Handover Connection and IP devices before reaching another VoIP device.

The Service ID (ASID), stored in the DHCP Option 82 Remote ID field, and TR-156 Circuit ID will be

inserted into the DHCP Option 82 request and can be used as a non-repudiated credential. It

recommended the Service ID is used as is returned as part of the service request, unlike TR-156 Circuit ID,

and will not change under normal operational conditions, i.e. does not change under faults or network

grooming.

The Service Provider can make use of DHCP Option 43, to deliver the ACS URL, and credentials. Within

Option 43, option code 254 allows the Service Provider to set a specific 'Serial Number' to identify the SIP

User Agent with the ACS. The Service Provider can later modify the ACS settings through the TR 098 / TR

069 parameter setting, to suit different ACS deployments, i.e. zero touch.

The SIP User Agent will initiate a TR-069 configuration request to the ACS. Both HTTP basic and digest

authentication are supported

When a Service Provider‟s ACS initiates a TR-069 session to the SIP User Agent, then this will be

authenticated with an HTTP connection request username and password.

The SIP User Agent does not support Secure Sockets Layer (SSL) or Transport Layer Security (TLS).


Higher Layer Interfaces

IP Characteristics

The two SIP User Agents require the following IP addressing characteristics:

Each SIP User Agent within the same ONT must use a different IP address.

The ONT will use IPv4.

The IP address range 192.168.1.0/24 and 192.168.2.0/24, cannot be used by Service Providers, as these

are required for management of the ONT by Chorus.

Configuring the SIP User Agent using DHCP

The Service Provider will provide the following services:

A DHCP, service that will configure the IP address of the ONT SIP UA.

A DHCP service that will provide the ACS URL, and, optionally, public username / password.

Provision of a DNS service if required.

The ONT supports DHCP Options 1, 3, 6, 12, 15, 43, 51, 53, 54, 55, 58, 59 and 61.

The following table shows the core parameters configurable using DHCP

Layer 4 Characteristics

SIP Signalling by default will use Port 5060, and will be carried over UDP.

Media and Voice-band Data (VBD) shall be carried as RTP, over UDP.

The SIP UA supports RTCP SR Records

SIP Interface

The following details the ONT SIP standards

Supported: RFC3261, RFC2327, RFC3264, RFC3262, RFC3311, RFC3325, RFC3515, RFC3960, and

RFC4028.

Partially Supported: RFC3265 (support NOTIFY from RFC3842), RFC3842 (NOTIFY).

Not supported: RFC3263, RFC3323, and RFC3350.

Other characteristics

Lawful intercept requirements are the responsibility of the Service Provider.

Usage billing information (Call Detail Records) is the responsibility of the Service Provider.


TR-069 Overview

Detailed information on the NGA Voice TR-069 implementation is documented in the NGA Voice

Technical User Guide.

Introduction

NGA Voice TR-069 management is performed through the communication between the NGA Voice SIP

User Agent on the ONT and an ACS. This allows the ACS to manage the SIP User Agent in a flexible and

systematic manner.

The ACS consists of a server machine running a manager application, such as OpenACS.

NGA Voice allows the ACS to provide the following functions:

Auto configuration and dynamic service provisioning;

Retrieval of status information to help resolve connectivity or service issues.

The NGA Voice SIP User Agent acts as an HTTP client and the ACS acts as the TR-069 HTTP Server. A

SOAP request from the ACS is sent over an HTTP request and the SIP User Agent's SOAP is returned via a

subsequent HTTP Post. The following table shows the TR-069 protocol stack:

TR-098 and TR-104 Data Model

TR-069 supports the parameters that are defined in the following two technical reports:

Establishment and Registration

The following diagram depicts the establishment of connectivity and registration of the ONT with the ACS.


TR-069 use case scenarios

NGA Voice supports the following TR-069 use case scenarios:

TR-104 Diagnostic Parameters Supported

NGA Voice supports the following diagnostic parameters:

Status: Indicates the status of the UNI-V.

CallState: Indicates the current status of the connection to the SIP ser Agent.


This provides Service Providers with real-time status of the NGA Voice service.


On-Boarding Process

The following approach is a suggested approach for onboarding NGA Voice.

To support this process, Chorus will provide:

Introduction to NGA Voice (this document)

NGA Voice Technical User Guide

Proposed Test Plan (see check list below)

Minor differences between the Service Provider, and the UFB network, may be addressed during

onboarding, supported by testing in the model environments. If modifications are required to the service

then they will need to follow the Chorus Co-Innovation model and will become the baseline configuration

for that Service Provider.

The Service Provider should fully test the following three key areas:

1. Inter-working of the Service Provider Soft-switch to the UFB network, specifically the SIP User Agent.

2. Testing of the Service Provider Provisioning system to the Chorus Provisioning systems

3. Operational interface and process.

The Chorus Co-Innovation Laboratory (CCIL) mimics the UFB network, and can therefore be tested with

the same network functionality as the production network. Using CCIL the Service Provider can test the

end user (analogue) interface through to the E-NNI to verify the service.

Check list

The following is a suggested checklist for consuming NGA Voice:



Operational Support

Operate Model

It is expected that the Service Provider will perform basic testing of a faulty service before they pass a

fault to Chorus

Where a Service Provider has performed basic testing, and cannot rectify the fault, or require assistance

to rectify a fault, then a fault will be presented to the Chorus Help desk.

The Chorus help desk will investigate the fault, but may require cooperation from the Service Provider to

test and validate actions.

In-service faults

TR-069 diagnostic messages can be used to determine the status of the ONT and call sessions.

It is recommended that Service Providers provide a link from their ACS and Soft-switch to the Chorus

Co-Innovation Lab connections to allow testing of the NGA Voice configurations.

If an NGA Voice service develops a fault after being in service then the Service Provider is expected to

verify:

1. Confirm that this customer service has previously been known to operate correctly; to

distinguish in-service faults from newly provisioned service, faults.

2. Check if the SIP User Agent is registered on the Service Provider Soft-switch; to determine if this is a

basic connectivity fault, or a feature fault.

3. Check if any Bitstream services to the same End User are functioning.

4. Use TR-069 to check the SIP User Agent status or call status.

5. Check that no service restrictions have been placed on the Customer, IE „Credit Barred‟.

6. Confirm that the correct ACS Configuration file has been delivered to the ACS Server.

7. Confirm that the DHCP Option 82 setting is correct.

8. Confirm that other customers through the same E-NNI are still working correctly; to ensure

the E-NNI itself is operating.

9. Confirm that an NGA service to the ONT is operational; to determine if the ONT itself is

operating, and connectivity through the network to the ONT exists.

10. Confirm that a “Ping” to the SIP User Agent can be executed; to confirm that the SIP User

Agent IP layer is operational.

Having run through these checks, to ascertain the Service Provider network is operating correctly, then the

Service Provider can pass the fault to Chorus who will execute the following tests:

1. Confirm there are no network events that would affect the customer; to determine if the

failure is actually to a network event.

2. Check that the ONT and NGA Voice are correctly provisioned, and conform to the details

provided by the Service Provider; to ensure the correct configuration of the SIP User Agent

3. Check no adverse alarms are being generated by the ONT, or the network path; to confirm the Chorus

systems show the ONT is operating correctly, and no alarms requiring further analysis are present.

4. Assist the Service Provider to debug the customer specific ACS configuration in the CCIL. This would

not be part of normal fault handling.

Documents

NGA Voice - Chorus Voice whitepaper... · PDF fileVersion '130820142432', printed from voice on November 03 2016. Voice – Access Virtual Private Line (Voice-AVPL)