Siemens HG 3500 V4 User manual

Communication for the open minded
Siemens Enterprise Communications
www.siemens.com/open
Documentation
HiPath 4000 V5
IP Solutions - HiPath Gateways HG 3500 and HG
3575
Service Documentation
A31003-H3150-S104-2-7620

Copyright © Siemens Enterprise
Communications GmbH & Co. KG 2009
Hofmannstr. 51, 80200 München
Siemens Enterprise Communications GmbH & Co. KG
is a Trademark Licensee of Siemens AG
Reference No.: A31003-H3150-S104-2-7620
The information provided in this document contains
merely general descriptions or characteristics of
performance which in case of actual use do not
always apply as described or which may change as
a result of further development of the products. An
obligation to provide the respective characteristics
shall only exist if expressly agreed in the terms of
contract. Availability and technical specifications are
subject to change without notice.
OpenScape, OpenStage and HiPath are registered
trademarks of Siemens Enterprise
Communications GmbH & Co. KG.
All other company, brand, product and service
names are trademarks or registered trademarks of
their respective holders.
Siemens Enterprise Communications
www.siemens.com/open
Communication for the open minded

gatewaysTOC.fm
A31003-H3150-S104-2-7620, 03/2009
HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation 1
Nur für den internen GebrauchService Manual HiPath 4000 V5 - IP Solutions - HiPath Gateways HG 3500 and
Service Manual HiPath 4000 V5 - IP Solutions - HiPath
Gateways HG 3500 and HG 3575 - Contents 0
1 Goal of this Document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 Key Words . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Fax or Modem Transmission and Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2.1 Without FMoIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2.2 With FMoIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.3 Codec Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.4 Voice Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.5 Jitter Buffer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.5.1 Jitter Buffer Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.5.2 Jitter Buffer Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.5.3 Considerations when Configuring the Delay for Static Jitter Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.5.4 Clock Drift with Static Jitter Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.5.5 Minimum Delay for Adaptive Jitter Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.5.6 Packet Loss Control in Adaptive Jitter Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.5.7 Parameters for Jitter Buffer Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.6 Runtime and Noticeable Effects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.6.1 Delay and Echo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.6.2 Delay and Hands-Free Talking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.7 Voice Encryption Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3 Architecture and System Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.1 Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.2 Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.3 Network Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.4 Network Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.5 Bandwidth Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.5.1 Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.5.2 Sampling Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.5.3 IP Overhead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.5.4 Required Bandwidth per Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.5.5 Voice Activity Detection (VAD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.5.6 DMC Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.6 B Channels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.6.1 B Channel Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.6.1.1 AMO BFDAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.6.1.2 AMO BCSU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.6.2 Automatic b channel reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.6.3 Displaying the B Channels currently Available/Configured (possible IP-Based Connections) . . . . . . . 39
3.7 Traffic Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4 Supported Gateways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.1 HG 3500 V4 (Common Gateway) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.1.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.1.2 Hardware and Loadware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.1.3 Scenarios and Protocols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Service Manual HiPath 4000 V5 - IP Solutions - HiPath Gateways HG 3500 and HG 3575 - Contents Nur für
A31003-H3150-S104-2-7620, 03/2009
2HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation
gatewaysTOC.fm
4.1.4 Board Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.1.5 Feature Capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4.1.6 Impact on Existing Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.1.7 Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.2 HG 3575 V4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.2.1 General Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.2.2 Hardware and Loadware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.2.3 Exchanging Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5 Features and Restrictions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
5.1 Gateway Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
5.2 Direct Media Connection (DMC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
5.3 Voice Compression. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
5.4 Voice Activity Detection (VAD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
5.5 Comfort Noise Generation (CNG). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5.6 Echo Cancellation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5.7 Redundant LAN Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.8 Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.8.1 Access for Administration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.8.2 Access to SNMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.8.3 Security in CorNetTC Registration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.8.4 H.235 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
5.8.5 Connecting IP Gateways to the Internet or via External Providers . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
5.9 Resource Manager (RM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
5.10 Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.10.1 Bit Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.10.2 Loadware-Update or Reset of the Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.10.3 Possible IP hops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
6 Communication Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
7 Load Concept for Gateway Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
7.1 Important Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
7.2 Notes on IP Gateway Loadware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
7.3 New Load Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
7.4 Updating Loadware with Web-Based Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
7.5 Updating Loadware with "LW Update Manager". . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
7.6 General Comments on Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
8 Save Configuration Data in Local Flash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
8.1 Feature Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
8.2 Startup Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
8.3 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
8.4 Special Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
9 Loadability of the FPGA on the STMI4/NCUI4 board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
10 Standby Board HG 3500 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
10.1 Feature Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
10.2 User Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
10.3 Service Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
10.4 Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
10.5 Service steps after the automatic switch over . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
10.6 Relevant AMOs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
11 DLS Client Bootstrapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

gatewaysTOC.fm
A31003-H3150-S104-2-7620, 03/2009
HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation 3
Nur für den internen GebrauchService Manual HiPath 4000 V5 - IP Solutions - HiPath Gateways HG 3500 and
11.1 Bootstrapping with "No PIN" PIN Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
11.2 Bootstrapping with "Default PIN" or "Individual PIN" PIN Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
12 HiPath Gateway HG 3575 V4 - Changing Parameters with AMO STMIB . . . . . . . . . . . . . . . . . . . . . . . 105
12.1 TYPE GLOBAL - Changing the Idle Bit Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
12.2 TYPE IFDATA - Changing the Interface-Specific Parameters of the Access Point . . . . . . . . . . . . . . . . . 106
12.3 TYPE SERVIF - Changing the Login and Password for Service Access. . . . . . . . . . . . . . . . . . . . . . . . . 107
12.4 TYPE ASC - Changing the Payload QoS Setting of the Access Point. . . . . . . . . . . . . . . . . . . . . . . . . . . 109
12.5 TYPE ASC - Setting the Codec List for DMC Connections, RTP Packet Size, Voice Activity Detection and
T.38 Fax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
12.6 TYPE DSP - Jitter Buffer Size of the Access Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
12.7 TYPE DMCDATA - Changing the Access Point Setting to Support Direct Media Connections. . . . . . . . 111
12.8 TYPE H323 - Changing the H323 Settings at the Access Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
12.9 TYPE JB - Configuring the Jitter Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
12.10 TYPE SIGQOS - Quality Monitoring for the Signaling Connection over IP . . . . . . . . . . . . . . . . . . . . . . 113
12.11 TYPE SNMP - Changing the Community Strings for Read Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
12.12 TYPE WBMDATA - Changing the Login and Password for WBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
12.13 TYPE GWSECTOR - Changing the Access Point Sector Number for the Resource Manager . . . . . . . 115
12.14 TYPE DLSDATA - Configuring DLS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
12.15 Resetting the Parameters to Default Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
13 General Information on How to Configure a HG 3500 V4 Common Gateway . . . . . . . . . . . . . . . . . . . 119
13.1 Changing the common gateway configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
13.2 AMOs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
13.3 Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
13.4 Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
13.5 Overview of Configuration Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
14 HiPath Gateway HG 3500 V4 - Changing Parameters with AMO CGWB . . . . . . . . . . . . . . . . . . . . . . . 123
14.1 TYPE ASC - Changing the Payload QoS Setting in HHS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
14.2 TYPE ASC - Setting the Codec List for DMC Connections, RTP Packet Size, and Voice Activity Detection
124
14.3 TYPE DMCDATA - Changing the HG 3500 Setting to Support Direct Media Connections . . . . . . . . . . . 124
14.4 TYPE DSP - Changing the DSP (Signal Processor) Setting at an HG 3500 . . . . . . . . . . . . . . . . . . . . . . 125
14.5 TYPE GLOBIF - Changing the Idle Bit Pattern and Interface-Specific Parameters . . . . . . . . . . . . . . . . . 126
14.6 TYPE GWSECTOR - Changing the HG 3500 Sector Number for the Resource Manager . . . . . . . . . . . 127
14.7 TYPE H235DATA - H.235-Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
14.8 TYPE MGNTDATA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
14.9 TYPE SERVIF - Changing the Login and Password for the Service Access. . . . . . . . . . . . . . . . . . . . . . 129
14.10 TYPE WBMDATA - Changing the Login and Password for WBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
14.11 TYPE JB - Configuring the Jitter Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
14.12 Resetting the Parameters to Default Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
15 Codec Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
15.1 HFA and Trunking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
15.2 IPDA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
16 Multiple Feature Support Configuration at the Common Gateway (Example) . . . . . . . . . . . . . . . . . . 135
16.1 Important Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
16.1 Configuring Functional Blocks with the AMO BFDAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
16.2 Configuring the Common Gateway Board with the AMO BCSU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
16.3 Configuring SIP Trunking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
16.4 Completed and Uncompleted Functional Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
16.4.1 Uncompleted functional block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
16.4.2 Completed configuration block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

Service Manual HiPath 4000 V5 - IP Solutions - HiPath Gateways HG 3500 and HG 3575 - Contents Nur für
A31003-H3150-S104-2-7620, 03/2009
4HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation
gatewaysTOC.fm
17 Command Line Interface CLI in HG 3500 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
17.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
17.2 General Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
17.3 Access control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
17.4 Gateway Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
17.5 Image/File Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
17.6 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
17.7 SSL for WBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
17.8 DLS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
17.9 Changing the Login and Password for WBM/CLI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
18 Command Line Interface CLI at HG 3575 V4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
19 SNMP Support HG 3500 / HG 3575. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
20 IP Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
20.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
20.2 Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
20.2.1 Payload . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
20.2.2 Signaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
20.2.3 SNMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
20.2.4 Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
21 HG 3500 / HG 3575 Diagnostic Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
22 Frequently asked Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

gateways_01_ziel.fm
Goal of this Document
A31003-H3150-S104-2-7620, 03/2009
HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation 5
1 Goal of this Document
This document aims to provide an overview of the new HG 3500 V4 and HG 3575
V4 gateways in HiPath 4000. Only the basic board configuration is described.
Detailed information on specific functions such as IP Distributed Architecture and
Access Point Emergency (IPDA & APE), HiPath Feature Access (HFA), Large
Enterprise Gatekeeper, etc. are provided in the corresponding sections.

Goal of this Document
gateways_01_ziel.fm
A31003-H3150-S104-2-7620, 03/2009
6HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation

gateways_02_terms.fm
Terms
Key Words
A31003-H3150-S104-2-7620, 03/2009
HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation 7
2 Terms
2.1 Key Words
In order to prevent confusion, a number of key terms which are used frequently
within the text are defined here in more detail.
Nodes: Designates a device with a port/connection in a network.
This can be a router, a HiPath 4000 CGW module or any computer.
Also frequently referred to as “Host“.
LAN segment: Part of a network in which all nodes communicate with each other
directly on Layer 2 (Ethernet MAC). The nodes are thus switched on
the same “shared“ medium and interconnected via hubs or Layer 2
switches. In other words, they communicate without routers (Layer 3).
The communication with nodes beyond this segment has to be
realized via routers.
IP address: A numerical Internet address comprising 4 sets of digits, e.g.
172.16.222.45. In this context, the term always designates the
individual, complete and unequivocal address of a node.
Network mask
(Netmask):
Internet addresses are broken down into network-specific and node-
specific sections. The size of these sections differs, depending on the
class of the address (determined by the first digit of the address).
Byte 1 2 3 4
Class
ANetwork [1 .. Node Node Node
BNetwork [128 .. Network Node Node
CNetwork [192 .. Network Network Node
The netmask allows subnets to be generated within a network.
Specific bits of the node section are used for the purposes of
addressing. The network mask specifies which parts of the IP address
are to be regarded as network/subnet sections by means of the
specified bits. The remaining digits (bits not specified in the mask)
designate the node section.
Network
address:
In this document, the term network address is used for the entire
network and subnet part of the IP address.
The network address is yielded by a bit-by-bit AND operation of any IP
address with the netmask.
VLAN tagging According to IEEE 802.1 p/q, there are two functions which are
controlled using a common tag: the priority and the VLAN ID. The
term VLAN tagging is generally applied once the tag is used -
regardless of what it is being used for. The same applies in the case
of IPDA. When reference is made to deactivating or activating VLAN
tagging (AMOs SIPCO or CGWB: VLAN), it is the tag that is meant, not
the VLAN function.
According to the standard there are three types of frames:

Terms
gateways_02_terms.fm
Key Words
A31003-H3150-S104-2-7620, 03/2009
8HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation
•Untagged Normal Ethernet frames without tagging
•Priority Tagged Ethernet frames with tagging
The priority bits are used
The VLAN ID is 0.
•VLAN Tagged Ethernet frames with tagging
The priority bits are 0,
The VLAN ID is > 0.
Some IP equipment vendors only allow priority bits to be used when
VLAN ID > 0 is set.
When tagging is being used, the IPDA components always use priority
tagging, but allow a setting of VLAN ID > 0
The priority bits are fixed according to the traffic type.
The values are specified in Table 2, “TOS values”.
TOS byte The Type Of Service byte is a component of the header for all IP
packets in accordance with RFC 791.
According to RFC 791 (Internet Protocol), the byte is split up as follows
(most significant -> least significant bit)
3 bits for precedence
111 - Network Control
110 - Internetwork Control
101 - CRITIC/ECP
100 - Flash Override
011 - Flash
010 - Immediate
001 - Priority
000 - Routine
3 bits for priority
D-T-R
Slight delay:
0 = Normal, 1 = Low
Throughput:
0 = Normal, 1 = High
Reliability:
0 = Normal, 1 = High
2 bits reserved
for future use
According to RFC 2474 (Differentiated Services), the six high-order
bits are used as DiffServ Code Point (DSCP), while the two least
significant bits are reserved.
Some of the values to be set are specified as 6-bit values without the
2 reserved bits, and others as 8-bit values (with the 2 reserved bits =
0).
With IPDA, the entire TOS byte is always specified. The two least
significant bits are always set to zero.
A pure DiffServ Code Point must therefore be moved 2 bits to the left
or multiplied by 4 in order to obtain the TOS byte setting for IPDA.

gateways_02_terms.fm
Terms
Fax or Modem Transmission and Detection
A31003-H3150-S104-2-7620, 03/2009
HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation 9
Figure 1 Example: Class B IP address, netmask and network address
2.2 Fax or Modem Transmission and Detection
2.2.1 Without FMoIP
The transmission of fax signals (or audio signals from modems) over IP is
generally not without its problems.
•With fax/modem transmission,
•voice compression and
•voice activity detection
must be disabled.
•Fax/modem transmission is very sensitive to packet loss in the IP network.
The effective packet loss rate in the network must be considerably lower for
fax/modem transmission than for voice transmission.
•Fax machines and modems are very sensitive to runtime fluctuations on the
transmission path, which is why there must be no automatic adaptation of the
jitter buffer.
The IPDA components evaluate the pilot tones of the caller fax machine or
modem and then make sure that the connection is optimized for modem
transmission.
IP address
172 16 222 45
10101100000100001101111000101101
Netmask
255 255 240 0
11111111111111111111000000000000
Subnet 1 1 0 1
Network address
172 16 208 0
10101100000100001101000000000000
Ta bl e 2 -1

Terms
gateways_02_terms.fm
Fax or Modem Transmission and Detection
A31003-H3150-S104-2-7620, 03/2009
10 HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation
2.2.2 With FMoIP
As of HiPath 4000 V2.0, the “FMoIP“ (FaxModem over IP) feature is used for the
transmission of fax and modem signals over the IP network.
FMoIP improvements
The FMoIP feature provides the following new functionality:
•DMC (Direct Media Connect) for fax/modem calls. This results in a maximum
of one IP hop (2 IP/TDM conversions) for fax/modem connections within a
local HiPath network. DMC is supported for HG 3500 / HG 3575. This is the
major improvement in comparison with the last version, where a switch back
to master call was performed after tone detection.
•The DMC endpoints HG 3500 and HG 3575 support G.711 F/M.
•T.38
T.38 is possible for
– IP trunking connections (H323 and H323A)
– SIP trunking connections (SIP-Q and native SIP)
– DMC connections from/to IPDA
T.38 is not possible for
– IPDA master connections
– HiPath 4000 SoftGate
IMPORTANT: When connecting a fax adapter to a HG 3500 (SIP
subscriber), DMC must be deactivated for this device (only then is T.38 trans-
mission possible).
If you want nonetheless to connect DMC for this device, the codec must be
set to G.711 (fax transmission with G.711, not T.38).
•RFC2833 and RFC2198 for fax/modem tones are supported for HG 3500/75
to transfer the fax/modem signals over IP.
•Enhanced DSP tone detection (incl. tone information transfer based on
RFC2833/RFC2198) for HG 3500/75 boards. Supported tones:
– call initiation tones CNG and CT (calling side)
– call answer tones ANS(CED), /ANS, ANSam, /ANSam (called side)

gateways_02_terms.fm
Terms
Fax or Modem Transmission and Detection
A31003-H3150-S104-2-7620, 03/2009
HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation 11
Requirements
•Using HG 3530 V2.0 board with AP1120 for fax/modem connection a
homogeneous HiPath 4000 V2.0 2nd Intro (as of SMR 8 of HiPath 4000 V2.0)
network with all V2.0 boards updated to FMoIP version is required.
•FMoIP Feature is a V2.0 improvement for multiple hops fax/modem
scenarios. This improvement through FMoIP can only be used, if all HG 3500/
3575 boards are updated to an FMoIP version (as of SMR 10 of HiPath 4000
V2.0 (PRB MSC10614)). Without update of all boards to the FMoIP version,
the old (still existing) fax/modem functionality of V1.0 and V2.0 1st Intro
network will be applied.Mixed mode for HG 3550 between FMoIP and non
FMoIP version implicate a G.711 FM instead of T.38 fax connection in case of
low speed fax communication. G.711 FM instead of T.38 increases the utilized
IP bandwidth. Using FMoIP version for all HG 3550 boards the T.38 fax
connection will be preferred for low speed connections.
Restrictions
•When DMC is not able to reduce the number of IP hops for a connection to
one IP hop, there will still be a certain risk of broken fax or modem
connections because of the resulting delay, even though a G.711 channel
optimized for analog data is chosen.
•Fax/Modem call: only supports basic call, no support for supplementary
services initiated on basis of an existing connection, such as consultation call.
Support of basic call includes forwarded calls (CFU).
•Interworking between v1.0 boards and v2.0 FMoIP boards is supported, with
the restriction that the FMoIP features are not used since v1.0 boards do not
support FMoIP functionality.
•Due to the variety of the available modem and fax types on the market, there
is no guarantee that all FMoIP scenarios will work with 100% reliability. The
different behaviors of the modem and fax types (e.g. tolerance) and the
typical IP conditions (jitter, delay etc.) can result in failed FMoIP scenarios.
•Clear Channel has to be disabled via AMO configuration because there is no
RFC2833/RFC2198 tone detection for Clear Channel. Each fax/modem call
should be configured as a regular voice call (G.711, G.729, ...).
T.38
T.38 is an ITU standard for sending fax messages accross IP networks in a real-
time mode.

Terms
gateways_02_terms.fm
Codec Standards
A31003-H3150-S104-2-7620, 03/2009
12 HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation
2.3 Codec Standards
To transmit an analog voice signal over digital paths, it must be converted to a
digital signal (and then back again). There are different methods for implementing
this codec, each of which offer different levels of voice quality and requires
different amounts of bandwidth.
Detailed information on the codec classmarks is provided in Table 20, “Classmark
handling for codec type” in the document "IP Distributed Architecture (IPA) and
Access Point Emergency (APE)".
2.4 Voice Quality
For the transmission of voice over IP networks, there are three other factors that
influence the subjective voice quality experienced by the customer:
•Delay
Occurs in the packetization of voice data (see Figure 2 Packet-by-packet
voice transmission) and in the transmission of packets. Compression codecs
(e.g. G.729) require processing time. In order to compensate for fluctuations
in the packet runtime (jitter), a buffer is inserted on the receiver side (jitter
buffer). The size of the jitter buffer also influences the overall delay.
• Packet loss
Packets can sometimes be lost during transmission in IP networks. Fill data
must then be inserted on the receive side in place of the required packet data.
•Jitter
Fluctuation of the packet runtime above or below a mean value, see Figure 3
Jitter: variation of the transmission delay. The jitter buffer must intercept these
fluctuations. The packet earmarked for use is lost if the deviation from mean
value is so great that it can no longer be intercepted by the jitter buffer. The
effect is the same as for packet loss in the network.

gateways_02_terms.fm
Terms
Voice Quality
A31003-H3150-S104-2-7620, 03/2009
HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation 13
Figure 2 Packet-by-packet voice transmission
Figure 3 Jitter: variation of the transmission delay
The effectiveness of both parameters also depends on the sample size (how
many milliseconds of voice per packet) and on the codec type.
Figure 4 Voice quality depending on delay illustrates an evaluation of voice quality
depending on delay.
1 ms
Transmission
runtime
30 ms
Transmission
runtime
Packetization delay
(sample size)
1 ms
ISDN: Byte-by-byte transmission, continuous data
Sender
Receiver
Transmitter
Receiver
IP: Packet-by-packet transmission, packet can only be sent when it is full
t
Sender Receiver
t
0
t
R
Transmission
Transmissionby
variousnetwork components
t
R max
t
R avg
t
R min
Variation of the
Mean value Worst case
t
0
delay
transmission delay
Jitter
IPNetwork
t

Terms
gateways_02_terms.fm
Voice Quality
A31003-H3150-S104-2-7620, 03/2009
14 HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation
Figure 4 Voice quality depending on delay
Table 1, “Voice quality depending on delay and packet loss rate” illustrates an
evaluation of voice quality depending on delay and packet loss rate.
For all solutions over IP, i.e. including HiPath 4000, configurations with multiple
IP-TDM (or TDM-IP) conversions in a connection should be avoided, as each
conversion creates a delay. This is because of the potential losses in voice
quality where the number of delays is too high. Every module in the HG 3500
family (and HG 3575 in the access point) as well as every terminal device
Scale of acceptance
Value Acceptance
0 - 5 Very good
6 - 10 Good
11 - 19 Satisfactory
20 or more Unsatisfactory
Delay
[ms]
Packet loss rate in %
< 1% 1% 1.5% 2% 2.5% 3% > 3%
50 046810 12 30
100 046810 12 30
150 046810 12 30
200 37911 13 15 33
250 10 14 16 18 20 22 40
300 15 19 21 23 25 27 45
350 20 24 26 28 30 32 50
400 25 29 31 33 35 37 55
Table 1 Voice quality depending on delay and packet loss rate
User satisfaction
0
50
60
70
80
90
100
100 200 300 400 500
One-way delay [30 ms] (with 65 dB echo attenuation)
Very
satisfied
Satisfied
Some
users
Many
users
Extremel
y
Table 2-1
%

gateways_02_terms.fm
Terms
Jitter Buffer
A31003-H3150-S104-2-7620, 03/2009
HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation 15
distributed directly via HFA has a IP-TDM conversion. The maximum number of
IP-TDM conversions should (not including HFA terminal devices) be no higher
than two.
2.5 Jitter Buffer
2.5.1 Jitter Buffer Functionality
Transfer packets can arrive with different delays in TCP/IP-based networks.
Because these delays cause interruptions, packets entering the data stream must
be verified. The jitter buffer provides temporary storage for IP packets. It can
balance out IP packet delays to a certain degree.
IP packets enter the jitter buffer in the order in which they arrive. Each packet
contains a time stamp, which is stored in the RTP header of the packet. The
actual order is determined using the packet time stamps. The jitter buffer ensures
that packets leave in the right order and in sync. An average time (average delay)
defines how long packets, which arrive at the expected time, are held in the jitter
buffer. Packets which arrive later than expected are held for a shorter period in
the jitter buffer; packets which arrive earlier than expected are held longer. If a
packet arrives so late that it can no longer be assigned, it is lost. In theory, packets
can also arrive so early that they cannot be assigned. This is, however, rarely the
case in practice.
Figure 5 Jitter buffer functionality illustrates the jitter buffer functionality.
If one or two packets are lost during voice transmission, this is not an immediate
problem. However, the delay should be as short as possible, as delays which are
too long compromise voice quality when making calls.
To ensure data integrity, the number of packets lost during data transfer should
be kept to a minimum. Delays, on the other hand, do not play a major role here.

Terms
gateways_02_terms.fm
Jitter Buffer
A31003-H3150-S104-2-7620, 03/2009
16 HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation
Figure 5 Jitter buffer functionality
2.5.2 Jitter Buffer Modes
As of HiPath 4000 V4, the jitter buffer "Legacy Mode" (JBMODE=0) is no longer
supported. If this is still set in the AMO using the parameter JBMODE=0, the static
jitter buffer (JBMODE=1) is used regardless, thanks to a mapping in the gateway.
The jitter buffer of the HiPath 4000 gateways HG 3530/50/70/75 can be operated
in two different modes, depending on the connection:
•Staticjitter buffer
• adaptive (dynamic) jitter buffer
The adaptive jitter buffer is designed specifically for voice transmission. While the
average packet delay remains constant in static mode, it automatically adapts to
the situation in adaptive mode. Figure 6 Difference between static and adaptive
jitter buffer illustrates the difference between static and adaptive jitter buffers in a
situation where several packets with longer delays arrive.
n-1 n-2 n-3 n-4
n
Jitter Buffer
Packet arrives on time
Scenario 1:
n-1 n-2 n-4
n-3 Delayed packet arrives
Scenario 2:
Buffer area for packets which arrive early
Key:
Buffer area for packets which arrive on time
Buffer area for packets which arrive late
Jitter Buffer
(can still be allocated)
n-1 n-2 n-4
n-5 Packet arrives too late
Scenario 3:
Jitter Buffer
Packet is lost
n-1 n-2 n-3 n-4
n+2
Jitter Buffer
Packet arrives too early
Scenario 4:
(can be allocated, is held longer in the buffer)

gateways_02_terms.fm
Terms
Jitter Buffer
A31003-H3150-S104-2-7620, 03/2009
HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation 17
In the adaptive jitter buffer, the average delay is simply the start value for the
average delay. This is automatically adjusted to the respective receive ratios
during operation (green line).
Figure 6 Difference between static and adaptive jitter buffer
2.5.3 Considerations when Configuring the Delay for
Static Jitter Buffer
The lower the average and maximum delay is set, the more natural voice
transmission will sound to subscribers. However this increases the danger of
packet loss and in turn the danger of information loss and distortions. Higher
delay values mean less packets get lost, however, it takes longer until a
subscriber hears what the other subscriber is saying. Extensive delays can lead
to communication difficulties. The following diagram illustrates this:
Measured time
Maximum delay (configurable)
Key:
Average delay (configurable, however, only the
Del
ay
packets
Static jitter buffer: Average delay is constant.
Packets with higher average delays
Adaptive jitter buffer: Average delay is variable
and is automatically adapted
Measured time
Del
ay
are not adapted.
for packets with higher average delays (however, only as far as the
maximum delay configured).
start value for jitter buffer)

Terms
gateways_02_terms.fm
Jitter Buffer
A31003-H3150-S104-2-7620, 03/2009
18 HiPath 4000 V5, IP Solutions - HG 3500 & HG 3575, Service Documentation
Figure 7 Settings for the static jitter buffer
When the HG 3500/75 board is being generated, generous values are set with
which most installations will start without any problem. In many cases, these
values can then be reduced selectively.
2.5.4 Clock Drift with Static Jitter Buffer
With digital voice transmission in ISDN, all transmission devices operate
synchronously. In other words, the volume of voice data per time unit is absolutely
the same for the sender and the receiver. For this purpose, transmission devices
are synchronized to a common clock pulse (clock signal).
With digital voice transmission over IP, the transmission devices operate
asynchronously.
Exception: IPDA access point with digital trunk connection can synchronize with
the clock signal.
This asynchronicity means that more or fewer packets are created per second at
the transmitting end than are expected at the receiving end. This discrepancy is
called clock drift.
Measured time
Maximum delay (configurable)
Key:
Average delay (configurable)
Del
ay
Received packets
Lost packets
Lower delay values:
Natural-sounding voice transmission, however some packets
Measured time
Del
ay
Higher delay values:
Voice transmission with noticeable delays, however, less packet loss
are lost