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Optimisation, 11.1.5 Call set-up, The OpenCom 510 uses a TOS byte Type of Service

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Voice over IP (VoIP) Fundamentals 11.1.4 Optimisation If you detect a large fluctuation in the propagation delay during measurement, this may also cause the voice quality to deteriorate. This may indicate a defective or overloaded line caused by bit-error or collision correction resulting from retransmission by the transmission procedure. An existing star-topology ethernet-network may uses a Hub as the central distributor of ethernet packets. A Hub repeats all ethernet packets received on all connected lines. This can cause substantial collisions and result in a high fluctuation in the propagation delay. If this is the case, use a modern switch component. Selective forwarding of ethernet packets ("Layer 2 switching") avoids collisions. Modern switch components also evaluate the TOS byte of IP packets, thereby providing the optimal prerequisites for VoIP telephony. Note: The OpenCom 510 uses a TOS byte ("Type of Service") value of 0xB8 for IP packets with VoIP data. This requests "Minimise Delay" and "Maximise Throughput" for IP packets marked with this value. 11.1.5 Call set-up Various IP-based protocols are used for system telephony via the Internet protocol ("IP") (see also Start Procedure starting on page 129). Multiple TCP connections are made between an IP telephone and OpenCom 510 for the telephone's start procedure, registration and signalling. Call data is directly exchanged between IP telephones using the RTP ("Realtime Transport Protocol") protocol. Channels on a Media Gateway (MGW) are allocated for making a telephone connection with an ordinary terminal or for dial tones. The MGW converts IP voice data into PCM data streams used with conventional telephony and vice versa. For this, IP voice data are exchanged between the IP telephone and the gateway. Tip: Switching between voice data channels may cause a slight delay in some circumstances. For example: when accepting a call on an IP telephone, headset users should wait about one second before answering. 120

Section	Page
OpenCom 510	1
Mounting and Commissioning	1
Contents	3
1. Features	11
2. Factory Settings	16
2.1 Telephony Functions	16
2.2 Authorisations	16
2.3 Internet Functions	19
3. Preliminary Information	21
3.1 Construction of the OpenCom 510	21
3.2 Scope of Delivery	21
3.3 Declarations of Conformity	22
4. Installation	23
4.1 Safety Precautions	23
4.1.1 General Instructions	23
4.1.2 Notes on the Mains Supply	24
4.1.3 Notes on EMC and Earthing	24
4.1.4 Notes on Installing the OpenCom 510	25
4.1.5 Notes on Installing Terminals	26
4.2 Installation, Ambient Conditions	26
4.3 Installation in a 19\	27
4.4 Installing Modules	28
4.4.1 Slots	29
4.4.2 Notes on Disconnecting the Mains Supply	30
4.4.3 Installing the Central Control Module	31
4.4.4 Installing Interface Cards	33
4.4.5 Installing a Power Supply Unit	35
4.5 Backplane	36
4.6 Uninterruptible Power Supply	39
4.7 Power Failure	39
5. Interfaces and Connectible Terminals	41
5.1 Overview	41
5.2 S0 Ports	42
5.2.1 Termination	43
5.2.2 External ISDN Ports (S0 External)	45
5.2.3 Internal S0 Ports	46
5.3 Upn Ports	46
5.3.1 Terminals Connected to Upn Ports	46
5.3.2 Technical Information	47
5.3.3 DECT Base Station Connection Variants	48
5.4 a/b Ports	50
5.4.1 Terminals Connected to a/b Ports	50
5.4.2 Technical Information	52
5.5 LAN Port	53
5.5.1 DSL Port	53
5.5.2 Service PC	54
5.6 COM Port	54
6. Accessories and Adapters (OpenPhone 61, 63, 65)	56
6.1 Upn Adapter	56
6.2 a/b Adapter	56
6.3 Audio Adapter	57
6.4 Approved Devices / Approved Accessories	58
6.5 Device Combinations	59
7. Extensions and accessories for system telephones (OpenPhone 71, 73, 75)	63
7.1 Power supply unit	63
7.2 Keypad extensions	64
7.3 Headset	66
8. Modules	67
8.1 Module Naming Conventions	68
8.2 Overview of Available Modules	69
8.3 MPS+1-AC	71
8.4 MC+1-3	74
8.5 MT+S2M1-1	78
8.6 MX+S01-8	82
8.7 MS+UPN1-8	85
8.8 MS+UPN2-8	87
8.9 MS+A1-8	89
8.10 MS+A1-4	91
9. Configuration	93
9.1 Brief Guide to Initial Configuration	94
9.2 Configuring the OpenCom 510	96
9.2.1 Preparing the Configuration	96
9.2.2 Starting the Web Console	96
9.2.3 Loading the Online Help	98
9.2.4 Finishing the Configuration	98
9.2.5 Preconfiguration	98
9.2.6 Offline Configurator	99
9.2.7 Remote Configuration	99
9.2.8 Codes for IP Configuration	101
9.2.9 Saving and Loading the Configuration	102
9.2.10 Receiving System Messages as E-Mail	102
9.2.11 Loading SW Updates	103
9.2.12 Resetting the System Data	103
9.2.13 Generating Your Own MoH Files	104
10. Configuration Examples	105
10.1 OpenCom 510 in Computer Networks	105
10.2 Introduction to TCP/IP	106
10.3 OpenCom 510 in a Serverless LAN	107
10.3.1 DNS Name Resolution	108
10.3.2 Internet Access	108
10.3.3 RAS Access	109
10.4 OpenCom 510 in a LAN with an IP-enabled Server	110
10.4.1 DNS Name Resolution	110
10.4.2 Internet Access	111
10.4.3 RAS Access	112
10.5 Branch Link	113
10.6 Useful Information on Internet Access	114
10.6.1 Costs	114
10.6.2 Using the Web	114
10.6.3 E-mail	115
10.6.4 NAT	115
11. Voice over IP (VoIP)	117
11.1 Fundamentals	118
11.1.1 Propagation Delay and Bandwidth	118
11.1.2 Latency and Packet Length	119
11.1.3 Voice Quality	120
11.1.4 Optimisation	122
11.1.5 Call set-up	122
11.1.6 Useful services	123
11.2 Media Gateway (MGW)	123
11.2.1 MG+ETH1-1	124
11.3 SIP Telephony	126
11.4 VoIP System Telephones	128
11.4.1 Device Properties	128
11.4.2 VoIP System Telephone Configuration	129
11.4.3 LAN DHCP Server	130
11.4.4 Start Procedure	131
11.5 OpenPhone IPC	133
11.5.1 Installation	134
11.5.2 Configuration	134
12. DECTnetIP	136
12.1 Properties	136
12.1.1 DECT base stations	136
12.1.2 Features	137
12.2 Configuration	138
12.2.1 Dual operation	139
12.2.2 Synchronisation	139
12.2.3 Setting up the WLAN function	140
12.2.4 Configuring for a remote location	143
13. PBX Cascading	147
13.1 Variants of PBX Cascading	147
13.2 Functionality of PBX Cascading	147
13.3 Putting a Cascaded PBX into Operation	148
13.3.1 Notes	151
13.4 Licensing Information	152
14. PBX Networking	153
14.1 Connections	154
14.1.1 Protocol: Q.SIG or DSS1	154
14.1.2 Master/Slave	155
14.1.3 L1 Clock	155
14.2 Types of Point-to-Point Connections	156
14.2.1 Direct Connection	156
14.2.2 Connection via an Active Transmission System	157
14.2.3 Connection via the Public Network	157
14.2.4 Connection via Q.SIG.IP	158
14.3 Configuration	159
14.3.1 Trunk groups	159
14.3.2 Routes	159
14.3.3 Numbering	160
14.4 Technical Details	162
15. Team Functions	163
15.1 Introduction	163
15.1.1 Explanation of Keys	163
15.1.2 Team Configuration	165
15.2 Examples of Use	166
15.2.1 Executive/Secretary Team	166
15.2.2 Three-member Team	168
15.2.3 Unified Team	169
15.2.4 Toggle Team	170
16. Call Queue	173
16.1 Introduction	173
16.1.1 Activation of Queues	174
16.1.2 Call Forwarding	174
16.1.3 Pickup	175
16.1.4 Hunt Groups	175
16.2 Examples of Use	175
16.2.1 Enquiry Station for an Operator with Two System Telephones	175
16.2.2 Group of Three Enquiry Stations	177
17. Multi-Company Variant	179
17.1 Configuring the Multi-Company Variant	180
17.1.1 Activating the Multi-Company Variant	180
17.1.2 Configuring and Managing Companies	181
17.1.3 Assigning Users	181
17.1.4 Assigning Trunk Groups/SIP Accounts	182
17.1.5 Allocating Routing Codes	182
17.1.6 Configuring the Company Exchange	183
17.2 Working with the Multi-Company Variant	183
17.2.1 Company Telephone Book	183
17.2.2 Making Calls Between Companies	184
17.2.3 Billing Charges per Company	184
18. Configuring the PC Software	185
18.1 PC Offline Configuration	185
18.2 Setting up TAPI	187
18.3 Setting up NET CAPI	189
18.4 Using the Systray Display	190
18.5 Browser for OpenCTI and OpenHotel	191
18.6 Setting up Video Telephony	192
18.7 Synchronising the PC Clock	193
18.8 Address Queries using LDAP	194
19. Configuration Guide	196
19.1 Overview	197
19.2 PBX Ports	198
19.3 LAN	199
19.4 WAN Settings	200
19.5 RAS Settings	201
19.6 Branch Settings	202
19.7 E-mail Function	203
19.8 E-mail Access	204
20. Frequently Asked Questions	205
20.1 General/Hardware	205
20.2 Telephony	206
20.3 DECT	208
20.4 LAN	209
20.5 Internet	210
21. Technical Data	213
22. Notes on disposal	216

Match case Limit results 1 per page

Voice over IP (VoIP)

Fundamentals

120

11.1.4 Optimisation

If you detect a large fluctuation in the propagation delay during measurement,

this may also cause the voice quality to deteriorate. This may indicate a defective

or overloaded line caused by bit-error or collision correction resulting from

retransmission by the transmission procedure.

An existing star-topology ethernet-network may uses a Hub as the central dis-

tributor of ethernet packets. A Hub repeats all ethernet packets received on all

connected lines. This can cause substantial collisions and result in a high fluctu-

ation in the propagation delay.

If this is the case, use a modern switch component. Selective forwarding of eth-

ernet packets (“Layer 2 switching”) avoids collisions. Modern switch components

also evaluate the TOS byte of IP packets, thereby providing the optimal prerequi-

sites for VoIP telephony.

Note:

The OpenCom 510 uses a TOS byte (“Type of Service”)

value of 0xB8 for IP packets with VoIP data. This requests

“Minimise Delay” and “Maximise Throughput” for IP packets

marked with this value.

11.1.5

Call set-up

Various IP-based protocols are used for system telephony via the Internet protocol

(“IP”) (see also

Start Procedure

starting on page 129). Multiple TCP connections are

made between an IP telephone and OpenCom 510 for the telephone’s start pro-

cedure, registration and signalling.

Call data is directly exchanged between IP telephones using the RTP (“Realtime

Transport Protocol”) protocol.

Channels on a

Media Gateway (MGW)

are allocated for making a telephone con-

nection with an ordinary terminal or for dial tones. The MGW converts IP voice

data into PCM data streams used with conventional telephony and vice versa. For

this, IP voice data are exchanged between the IP telephone and the gateway.

Tip:

Switching between voice data channels may cause a slight

delay in some circumstances. For example: when accepting a

call on an IP telephone, headset users should wait about one

second before answering.