2.5.4  
Example of Application of Thumb Rule 
 
In this example, a calculation is made on the basis of a standard configuration to illustrate use of the thumb rule.

2.5.4.1  
HiPath 3000/5000 V8 Configuration 
Number  
Type  
100  
Anate (analog telephones, terminal devices)  
100  
Digital terminal devices  
20  
Digital terminal devices with CTI-controlled functions  
20  
IP phones  
1  
Call pickup group consisting of two analog telephones and eight digital telephones  
5  
ACD agents of digital telephones with 32 calls per hour and display update every 5 seconds  
2  
Attendant consoles  
60  
Digital trunks to CO, of which 5 are for ACD application  
30  
Digital trunks to other systems via TDM (CorNet-N)  
The calculations are made using default traffic values. The thumb rule produces the following results:
100 · 3.4 +  
Anate  
(100 + 20) · 6.3 +  
Digital devices, but without ACD agents  
20 · 7.3 +  
IP phones  
5 · (179 / 5 + 65 · 32 / 16) +  
ACD agents (32 calls per hour and agent, i.e. C = 32/16)  
1 · 4.8 +  
One ACD group  
2 · 252 +  
Attendant consoles  
55 · 22.9  
Digital trunks minus the 5 ACD trunks  
30 · 18.9 +  
Networking trunk via TDM  
20 · 1.7 +  
Additional overhead for the 20 CTI-controlled terminal devices  
1 · (0.06 · 9 · 10 + 0.48 · 9 · 8)  
Call pickup group  
= 4,480  
Total number of points  
According to Table 2-14 , 22,600 points are available for HiPath 3800. Implementation with Hi-Path 3800 is, consequently, possible.

2.5.4.2  
HG 1500 Configurations 

2.5.4.2.1  
IP Trunking with TDM Terminal Points Only 
A HiPath 3800 system is networked with another system via an IP trunking link with 32 B channels. The codec G.711 with a sample rate of 20 ms (without encryption) is used for the IP trunking link. This requires an STMI2 module (2 DSPs on board = 32 voice channels are supported).
 Figure 2-8   IP Trunking with TDM Terminal Points Only
 
Calculation:
32 gateway channels via LAN 1 should be included in the calculation. If more than 16 channels are required, the feature "Enhanced B Channels" must be activated. The signaling load must also be taken into account.

 Table 2-29   IP Trunking Calculated with TDM Terminal Points Only
 Function  
 Formula  
 Points  
Signaling: IP-Phones (without H.235)  
 96 · 0.68  
 65  
Signaling: PBX networking channels (without H.235)  
 16 · 3.2  
 51  
Gateway channels: payload (G.711/20ms)  
 31 · 11  
 341  
Total  
   
 477  
With a permissible maximum points total of 980, this scenario is feasible. However, this sample calculation does not apply for HXGS/R3. This is because the static configuration rules only allow a maximum of 16 channels per board card.

2.5.4.2.2  
IP Trunking and HFA Clients 
A HiPath 3800 system with 96 HFA clients and additional TDM subscribers is networked with other nodes via an IP trunking link with 16 B channels. For 96 HFA terminal points, 15 gateway channels with 0.1 erl per terminal point are required.
The codec G.711 with a sample rate of 20 ms (without encryption) is required both for the IP trunking link and for the HFA terminal points. This requires an STMI2 module (2 DSPs on board = 32 voice channels are supported).
 Figure 2-9   IP Trunking and HFA Clients
 
Calculation:
Thirty-one gateway channels via LAN 1 should be taken into account. If more than 16 channels are required, the feature "Enhanced B Channels" must be activated. Firewall and encryption are not possible in this example. The signaling load (16 PBX networking channels and 96 HFA clients) must also be taken into account.

 Table 2-30   Calculation for IP Trunking and HFA Clients
 Function  
 Formula  
 Points  
Signaling: IP phones (without H.235)  
 96 · 0.68  
 65  
Signaling: PBX networking channels (without H.235)  
 16 · 3.2  
 51  
Gateway channels: payload (G.711/20ms)  
 31 · 11  
 341  
Total  
   
 477  
With a permissible maximum points total of 980, this scenario is feasible. However, this sample calculation does not apply for HXGS/R3. This is because the static configuration rules only allow a maximum of 16 channels per board card.

2.5.4.2.3  
IP Trunking via LAN and WAN (ISDN/PPP) 
A HiPath 3800 system (head office) is connected to a second system (branch office 1) via an ISDN connection with 2 PPP channels (S0), and to a third system (branch office 2) via a direct LAN connection.
Voice over PPP with codec G.729 and a sample rate of 60 ms without encryption is implemented for PBX network connection to the second system. Six voice channels are consequently supported via the two PPP channels (S0).
8 voice channels are sufficient for the PBX networking connection to the third system (branch office 2). Codec G.729 with a sample rate of 20 ms without encryption is used for this connection.
At head office, 6+8=14 PBX networking channels must be configured, while 6 PBX networking channels must be configured at branch office 1, and 8 PBX networking channels configured at branch office 2.
One STMI2 (2 DSPs on board supporting up to 32 voice channels) is sufficient for this purpose.
 Figure 2-10   IP Trunking and Node Connection via ISDN (PPP)
 
Calculation for head office:
6 voice channels over PPP must be calculated for branch office 1. The points for G.729 with a packet assembly of 3 (60ms) must be used. 8 gateway channels via LAN 1 must be calculated for branch office 2. The signaling load (14 PBX networking channels) must also be taken into account.

 Table 2-31   Calculation for Head Office
 Function  
 Formula  
 Points  
Signaling: PBX networking channels (without H.235)  
 14 · 3.2  
 45  
Gateway channels: payload (G.711/20ms)  
 8 · 39  
 312  
PPP channels: voice with G.729 and a packet assembly of 3  
 6 · 54  
 324  
Total  
   
 681  
With a permissible maximum points total of 980, this scenario is feasible.

2.5.4.2.4  
IP Trunking with VPN (Voice Only) 
2 HiPath 3500/3550 systems should be connected via VPN with a HiPath 3800 system. At head office (HiPath 3800), only TDM telephones are connected. 8 voice channels via LAN2 are available for the connection to the branch offices.
Each branch office (HiPath 3500/3550 system) is equipped with 30 HFA telephones and 8 gateway channels for the connection with the ISDN CO. 4 voice channels are also available for the connection to head office. The codec G.711 with a sample rate of 20ms is used for the VPN networking. The connection between the head office and the branch offices should be configured via the Internet using an AES-encrypted VPN tunnel.
For this configuration, the HiPath 3800 requires one STMI2 (2 DSPs on board for 32 channels), while the HiPath 3500/3550 systems each require one HXGS3 (1 DSP on board for 8 channels).
 Figure 2-11   VPN Networking (Voice Only)
 
Calculation for head office (HiPath 3800)
8 gateway channels via LAN2 with AES encryption must be calculated. In order to use the encryption feature, the option "Enhanced B Channels" must be deactivated. The signaling load must also be taken into account.

 Table 2-32   Calculation for Head Office (HiPath 3800)
 Function  
 Formula  
 Points  
Signaling: PBX networking channels (without H.235)  
 8 · 3.2  
 26  
Gateway channels: G.711 with VPN and AES  
 8 · 89  
 712  
Total  
   
 738  
With a permissible maximum points total of 980, this scenario is feasible for head office.
Calculation for each individual branch office (HiPath 3500/3550):
4 gateway channels via LAN2 with AES encryption, and 8 gateway channels from HFA telephones to the local ISDN CO (via LAN1) must be calculated. The signaling load must also be taken into account.

 Table 2-33   Calculation for Each Individual Branch Office (HiPath 3500/3550):
 Function  
 Formula  
 Points  
Signaling: IP phones (without H.235)  
 30 · 0.68  
 20  
Signaling: PBX networking channels (without H.235)  
 4 · 3.2  
 13  
Gateway channels: payload (G.711/20ms)  
 8 · 39  
 312  
Voice channels: G.711 with VPN and AES  
 4 · 89  
 356  
Total  
   
 701  
With a permissible maximum points total of 780, this scenario is feasible for the branch offices.

2.5.4.2.5  
Standalone System with Home Offices connected via VPN 
8 home offices are to be connected to a HiPath 3800 system. Teleworkers use G.723 with a sample rate of 30 ms. Data can also be transferred at 512 Kbps in both directions via a 1-Mbps SDSL connection. The average packet length is 500 bytes. VPN should be used with AES encryption. This configuration requires 1 STMI2 (2 DSPs on board for 32 channels).
 Figure 2-12   VPN Voice and Data, Home Office Connection
 
Performance calculation:
G.723 is generally configured for home offices. As VPN is required for the DSL connection, the option "Enhanced B Channels" must be deactivated. The HFA terminal point signaling load must also be taken into account.
When calculating the data traffic load, the upstream and downstream packet rates must be calculated from the average packet length.

 Table 2-34   Performance Calculation
 Function  
 Formula  
 Points  
Signaling: IP phones (without H.235)  
 8 · 0.68  
 5  
Voice channels: G.723 with VPN and AES  
 8 · 60  
 480  
Data (LAN): VPN and AES with 500 bytes upstream  
 128 · 1.19  
 152  
Data (LAN): VPN and AES with 500 bytes downstream  
 128 · 1.19  
 152  
Total  
   
 789  
With a permissible maximum points total of 980, this scenario is feasible.
Bandwidth calculation:

 Table 2-35   Bandwidth Calculation
 Function  
 Formula  
 Points  
Voice channels: G.723 with VPN and AES  
 8 · 44.3  
 354  
Data (LAN): VPN and AES with 500 bytes  
 512  
 512  
Total  
   
 866  
A 1Mbit/s connection is sufficient for the customer.

2.5.4.2.6  
VPN Networking with Data and Voice Connections 
A 1000 Kbps duplex data connection between 2 HiPath 3800 systems should be configured via a 2 Mbps SDSL interface. The average packet size should be 500 bytes. The SDSL connection should also be used for trunk connections with G.729 and a sample rate of 20ms. The SDSL line is connected to LAN2. The maximum possible number of additional IP trunking channels with G.729 should be calculated.
 Figure 2-13   VPN Networking
 
Performance calculation:
The required data traffic performance must first be determined. The upstream and downstream packet rates must therefore first be calculated from the average packet length.

 Table 2-36   Performance Calculation (1)
 Function  
 Formula  
 Points  
Data (LAN): VPN and AES with 500 bytes upstream  
 250 · 1.19  
 298  
Data (LAN): VPN and AES with 500 bytes downstream  
 250 · 1.19  
 298  
Total  
   
 596  
With a permissible maximum points total of 980, this leaves 980-596=384 points for IP trunking channels. For each IP trunking channel, one PBX networking channel and one gateway channel with VPN and AES is required. In other words, 3.2+89=92.2 points are required per trunking channel. If the remaining points are divided by the number of points per channel and rounded off, this results in 384/92.2=4 channels.

 Table 2-37   Performance Calculation (2)
 Function  
 Formula  
 Points  
Signaling: IP phones (without H.235)  
 4 · 3.2  
 13  
Gateway channels: G.729 with VPN and AES  
 4 · 89  
 356  
Data (LAN): VPN and AES with 500 bytes upstream  
 250 · 1.19  
 298  
Data (LAN): VPN and AES with 500 bytes downstream  
 250 · 1.19  
 298  
Total  
   
 965  
With a permissible maximum points total of 980, this scenario is feasible.
Bandwidth calculation:

 Table 2-38   Bandwidth Calculation
 Function  
 Formula  
 Points  
Voice channels: G.729 with VPN and AES  
 4 · 60  
 240  
Data (LAN): VPN and AES with 500 bytes  
 1000  
 1000  
Total  
   
 1240  
A 2Mbit/s connection is sufficient for the customer.

2.5.4.2.7  
IP terminals/clients for ISDN and ITSP connection in HiPath 3800 

Conditions  
For this scenario, the following conditions apply:
 •   One hundred IP terminals/clients (without H.235) are connected to HiPath 3800.
 •   It should be possible to connect eight simultaneous calls to the ISDN CO and 8 simultaneous calls to the ITSP.
 •   Voice and data traffic into the Internet take place via an external router, which also handles the firewall functionality.Therefore, the "Enhanced B-Channels" feature in the WBM of the HG 1500 must be activated.
 •   One STMI2 board is to be deployed.

Configuration instructions  
For signaling, the IP terminals/clients and the signaling for the calls to the ITSP must be taken into account. Eight gateway channels to the ISDN CO are needed for the 8 simultaneous calls. No gateway channels are needed for the 8 simultaneous calls to the ITSP due to the "IP/IP e2e payload via enterprise proxy" feature.

Graphical overview  
 Bild 2-14   IP terminals/clients for ISDN and ITSP connection in HiPath 3800
 

Calculation  

 Tabelle 2-39   Power requirements for ISDN and ITSP connection in HiPath 3800
 Functionality  
 Formula  
 Points  
Signaling without H.235 security (independent of "Enhanced B-Channels" setting)  
100 x IP terminals/clients, 8 calls per hour  
 100 x 0.68  
 68  
Payload data ("Enhanced B-Channels" setting is activated)  
Gateway channel via LAN 1 without encryption  
24 x G.711
(reception: 20 ms/transmission: 20 ms)  
 24 x 11  
 264  
Sum  
 332  

Conclusion  
The calculated power requirement of 332 points is below the total performance of 980 points that the STMI2 board can make available. The configuration can be implemented.

HiPath 3000/5000 V8, Service Documentation, Issue 10   up Top
Disclaimer & Copyright   ID: P31003H3580S100017620   2011-01-24