Media Gateway Testing Technical Overview

Shri Balla

2006

MGW Architecture

PCs on LAN

IP Phones on LAN

Fax

Analog phone CA /MGC

PSTN

SBC

CSCF cloud

PBX

MediaServer

Analog phone

SOLUTIONS Channel bank Data services Integrated services

T-GW

S-GW

ISUP

MGW Ethernet T1

IP cloud

CAS/PRI

Test tools Entity Capacity/Feature

Analog/Digital Bulk Call generator

192 simultaneous calls , configurable call parameters

Network impairment Network attacks, Deformed messages, Packet Loss Jitter, Delay

VoIP Bulk Call generator 50,000 RTP streams 100,000 SIP call BHCA

Data traffic Upto 64mbps with mixed traffic profiles, precedence

Call agent, Media Server, SBC

Standard capabilities

PBX emulation Asterisk

IP phones Pingtel , Cisco

Media GW Standard equipment such as Audiocodes, Cisco

Voice Quality Any vendor stack already benchmarked with PSQM, MoS

Accessories Switches, Routers

MGW Feature List Feature List Feature List Feature List

NAT/PAT Static NAT NAT Bypass

DTMF RFC2833 RADIUS Authentication DIAMETER Authentication

PPP MLPPP G729a Support

Frame Relay G.711mu/a-law MGCP

Telnet/SSH/RS-232 G.726-16/24/32/40 G729ab 16/24/32/40

DHCP Server/Client/Relay LAN Port Debugging

Secondary Call Agents

BootP Relay DNS relay/resolver MEGACO

WAN port Debugging NTP IP-WAN

T.38 with Fax/Modem Bypass

Secondary Ethernet IP Addresses

IP DS0 Management

Firewall QoS with IP TOS, priority queue

CLASS and CENTREX features

MGW Feature List … Continued Feature List Feature List

Voice and data on same T1 SNMP v2 and v3

FXS SYSLOG

V.35 BootP

FXO ALG for advanced SIP clients

V.90 Software upgrade/downgrade

Spanning Tree Configuration via TFTP

RIP v1, v2 Traceroute

OSPF VPN

PAP/ CHAP VLAN

Interoperability testing Features Features

Call Origination / Termination with Media , RTP Payload type

Call Waiting, Call reject

Call Failure codes Call Hold

Session audits Blind Call Transfer, CFNA

Audible Ringback, Local ringback, remote ringback, Early media

3Way Calling

Dial plan FAX – T.38, pass through

SDP parameter conformance PSTN to/from using SIP

DTMF – raw, RFC2833, INFO method PSTN to/from using MGCP

Codec Offer/Answer PSTN to/from using MEGACO

Codec Renegotiation Echo cancellation , VAD , Silence suppression

Voice Mail/Message Waiting Indicator (MWI) Caller ID, Tone detection

Protocol Messages SIP MEGACO MGCP

REGISTER ADD RSIP

INVITE MODIFY RQNT

ACK SUBTRACT NTFY

CANCEL MOVE CRCX

OPTIONS AUDITVALUE MDCX

NOTIFY AUDITCAPABILITY DLCX

BYE NOTIFY AUEP

INFO SERVICE CHANGE AUCX

PRACK EPCF

REFER

SUBSCRIBE

UPDATE

Category Scenario

VoIP stress Bulk calls with- Mixed traffic - Voice and data with MLPPP Combination – LAN/WAN Combination - Simultaneous originations

VoIP performance Codec and ptime variation with bulk calls G711, G726, G729 20/30/40

VoIP packetization time codec and ptime negotiation with LCO and SDP as variables

VoIP QoS voice prioritization(TOS)

Timers Protocol timers . For example in SIP – Timer A to K

Reliability Long duration calls(min 72 hrs) , MTTF 24 hr BERT of an RS232 port

RADIUS/DIAMETER Authorization , Authentication tests

FXS/FXO LS/GS, CPD parameterization

WAN PPP, MLPPP, FR, DS0 cross-connects

Test Scenarios

Test Scenarios - 2 Category Scenario Alarms Transmission- LOS, LOF , AIS alarm forwarding

Configuration - SNMP traps, SNMP walks Alarms - LED T1 – Normal, BPV, LOS, LOF, Loopback , remote alarm

Router(IP) – Link, collision, 10/100, Rx/Tx, Boot Voip – Link, collision, 10/100, Rx/Tx, Boot, Voip active/inactive/CA unreachable

NAT, Firewall NAT /PAT tests – static, dynamic Firewall filters – ingress, egress Combination - numbered/unnumbered WAN Combnation – Nessus port scan and exploits

DHCP Server and Client configs

DNS Basic DNS tests

NTP Configure to use NTP server primary/secondary

Syslog Syslog levels, CDR

Benchmarking Various benchmarks with various load parameters Example - 240 voip calls, G729a, 40ms, MoS 3.6, Network Delay max 140ms (G.114)

Calibration Calibration of analog parameters, tx/rx gain , DSP - echo tail length , RTP QoS, Jitter buffer

Test Scenarios - 3 Category Scenario

Service cards Card swap, resets, Card extraction/ insertion

Analog Transmission DS1 - id, port, Linecode, Framing, Loopdetect, linebuildout DSO – slot, port , channel, signalling(ls/gs), traffic(voice/data)

Routing OSPF, RIP Throughput configurations – 3000 packets/sec (64,128,256 byte size)