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6.5.2 |
IP Network and Application Server Requirements |
6.5.2.1 |
Adequate Connection Bandwidth |
| The customer network must fulfill the following requirements to ensure that voice information is transmitted successfully via LAN: |
| • | Switched LAN with 10/100 Mbps |
| • | Fixed IP addresses |
| • | Each component must have its own port at the switch (no HUBs as concentrators) |
| • | Pure Microsoft TCP/IP network (not a Novell network with SPX) |
| • | QoS, ToS and DiffServe (see below) |
| Although use in shared environments is possible, it is neither approved nor recommended, as there is no guarantee of quality. The HiPath server can also be operated in networks with routing components |
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6.5.2.2 |
Bandwidth |
| The bandwidth for voice must be available in the network at all times. For this reason, network measurement and analysis is carried out before installing the components. |
Why Measure the Network? |
| The following data is required to calculate the required bandwidth for voice transmission in an IP network in relation to the number of simultaneous connections: |
Bandwidth for voice information |
| All values refer to the lowest packet assembly level. The bandwidths in the WAN are only valid if the multilink and segmenting parameters have not been set. |
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Bandwidth Requirements for Additional Services: |
| The specified values represent the load in relation to a maximum call volume of 1400 BHCA (this is the maximum traffic with a connected call center solution). |
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Bandwidth Requirements for Administration (valid only for HPCO): |
| The specified bandwidth represents the worst case scenario. In other words, an entire CDB is sent to the server from the HiPath node every 30 seconds (max.) as a result of the synchronization process configured in the system. |
| It is difficult to define an accurate value at the moment due to the lack of data from the field. However, the bandwidth requirement will, in practice, be well below 132 Kbps, or there will be short-term peaks during which this value will be required by the network. |
| In practice, the most frequent application is the call up of key programming by users. A block of 64 KB is transferred in this process. An accepted period of 30 seconds for the transmission process results in bandwidth requirements of 18 Kbps. |
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Accordingly, the minimum bandwidth required is as follows: |
| The necessary bandwidth must be calculated using N as the number of simultaneous connections: |
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| N = number of simultaneous voice connections |
| When configuring fax or modem transmissions using the formula described above (outband transmission) the following are also required for each configured connection: |
| • | For fax group 3 (V.17, 14 Kbps): approx. 20 Kbps |
| • | For modem connections (V.34, 33.6 Kbps): approx. 40 Kbps |
6.5.2.3 |
Requirements of Delay Times |
| For natural communication, the delay should amount to a maximum of 50 ms (one-way delay) for voice connections (network delay). Delays of more than 50 ms in one direction impair natural communication. The effect is similar to that experienced with voice connections over satellite. The maximum number of HOPs must not exceed 15. |
| Priority control is a particularly efficient means of reducing the delay (see next section). Please proceed with caution if the network is operated using lines with a low bit rate (for example, connection of a branch to headquarters at a rate of 128 Kbps). The maximum number of trunk lines can be determined by calculating the necessary bandwidth. |
6.5.2.4 |
Provision of QoS in Data Networks |
| To guarantee the Quality of Service (QoS) described in the two previous sections, the following standards must be met: |
| • | All the components involved in transmitting voice data must support min. IEEE 802.1q (layer 2). |
| • | In addition, all components require routing according to the Diffserv standard RFC 2474 and the ToS standard (Type of Service) RFC 791. |
6.5.2.5 |
Quality Assurance Procedures to be Supported |
| • | Quality of Service (QoS) procedures in accordance with IEEE 802.1q (layer 2) |
| • | Type of Service (ToS) in accordance with RFC 791 (layer 3), packet prioritization |
| • | Differentiated Services (DiffServ - DS) procedure in accordance with RFC 2474 (layer 3) |
6.5.2.6 |
Maximum Package Losses |
| A maximum packet loss of 3% is tolerated. The reduced voice quality associated with packet loss is greater for G.723.1 and G.729 than for G.711. |
6.5.2.7 |
Minimization of Broadcast/Multicast Traffic |
| In accordance with the rules of good network design, broadcast/multicast traffic should be kept to a minimum. The use of routers/layer 3 switches to structure the network (for example VPM) or the use of layer 2 switches can help detect multicasting traffic. |
6.5.2.8 |
Requirements for Standalone Systems: |
| • | Switched or shared LAN (Ethernet IEE 802.3/802.3 u) with 10 or 100 Mbps |
| • | Pure Microsoft TCP/IP network (not a Novell network with IPX/SPX) |
| • | Fixed IP addresses (no DHCP) |
| • | The bandwidth required for transferring additional services (CDR and ACD/TAPI information) must be taken into account. If the bandwidth is sufficient, a second protocol (e.g. Novell) may be possible. |
6.5.2.9 |
Adaptation of QoS Classes to Oscar |
| Standardization according to the "HiPath QoS Strategy" involves adjusting the assignment of QoS classes on HG 1500 and in WBM. |
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| HiPath 3000/5000 V9, Service Documentation, Issue 7 | up  |
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| Disclaimer & Copyright | ID: P31003H3590S100017620 | 2012-06-25 |