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26 BSS21444 Packet Abis Security

26 BSS21444 Packet Abis Security

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Flexi EDGE BTS Feature Descriptions



4. The BTS (CMP Client) retrieves BTS Certificate from CA (CMP server).

BSC/BTS firewall functionalities

The main functionality of the firewall is to protect a network from external attacks by filtering the traffic. The filtering is done in a way that the service provided by NE still works

fine. Usage of firewalls for incoming Abis packets is recommended for all the planes.

Export Classification Control (ECC)

ECC in general does not allow exporting cryptographic algorithms to some countries.

ECC is not a static topic. It may change, every day, to which countries encryption algorithms can be exported.

Benefits for the Operator

CAPEX/OPEX savings for the operator. Operators who intend to use public Packet

Switched Networks for the transport solution will certainly face security issues when they

implement a native IP capability. This Packet Abis Security solution offers a fully integrated security capability without the need for external hardware. It will also simplify

maintenance since it is managed by existing network elements.

Requirements









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NetAct OSS 5.2 CD Set 3

The BSC3i 1000/2000 or Flexi BSC with supporting interface module is required.

The FIYA/FIQA Module is required for the Flexi EDGE (or Flexi Multiradio) BTS. The

FIYB and FIQB modules may also be utilised.



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Transmission



Flexi EDGE BTS Feature Descriptions



8 Transmission

8.1

8.1.1



Basic transmission

Abis Trunk Transmission for E1 (ETSI) interface

Up to four full rate (FR) or Enhanced Full Rate (EFR) speech channels, or up to eight

Half Rate (HR) speech channels, are multiplexed on a single 64 kbit/s PCM timeslot. It

is possible to create point-to-point star, multidrop chain or remote star transmission connections between BSC and BTS sites. This flexibility ensures that all kinds of transmission needs are fulfilled: traditional star configuration, economical multidrop chains, and

reliable multidrop loops are all possible.

Up to 12 TRXs are supported on a single 2 Mbit/s PCM line. See also BTS2503 Compressed Abis timeslot allocation.

Abis Trunk Transmission Allocation is implemented using the standard G.703 2 Mbit/s

PCM frame structure.

For more information, see BSS Transmission Configuration in BSC/TCSM Product Documentation.

Interaction with other features

BSS30285 Activation of additional two E1/T1 interfaces



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Flexi EDGE BTS Feature Descriptions



8.1.2



Abis Trunk Transmission Allocation for T1 (ANSI) Interface

Up to four full rate/enhanced full rate (FR/EFR), and eight with Half Rate (HR) speech

channels are multiplexed on a single 64 kbit/s PCM timeslot. It is possible to create

point-to-point star, multidrop chain or remote star transmission connections between

BSC and BTS sites. This flexibility ensures that all kinds of transmission needs are fulfilled: traditional star configuration, economical multidrop chains, and reliable multidrop

loops are all possible.

Up to 10 TRXs are supported on a single 1.5 Mbit/s PCM line. See also BTS2503 Compressed Abis timeslot allocation. This feature is implemented using the standard T1.403

PCM frame structure.

The T1 TRAU supports Extended Super Frame (ESF) and SF/D4 framing. The ESF

supports CRC-6 checks and 4 kbit/s data link for performance management.

Interaction with other features

BSS30285 Activation of additional two E1/T1 interfaces



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Flexi EDGE BTS Feature Descriptions



8.1.3



Abis Trunk Signalling

Radio Signalling Link is a logical link between the BSC and the BTS in Layer 2. The RSL

is identified by a functional address known as Service Access Point, SAPI=0. Radio signalling links over the Abis interface are addressed to different units by Terminal Endpoint

Identifiers, TEI. The TEI values are fixed and correspond to the TRX-id. The TEI management is not used.

One signalling channel is used for each transceiver (TRX) and one for each BTS base

control function (BCF). Alternative signalling speeds are available: 16 kbit/s, 32 kbit/s,

or 64 kbit/s. The selection of the signalling speed is done in the commissioning phase

on BTS basis. The same selection is also done on the BSC site when channel configuration is defined.

Normally, 16 kbit/s TRX signalling speed is recommended for the FR operation. 32 kbit/s

TRX signalling rate is recommended for the HR use.

At the BCF signalling rate of 64 kbit/s, the SW downloading time needed is approximately four times shorter than with 16 kbit/s signalling.



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Flexi EDGE BTS Feature Descriptions



8.1.4



Network Synchronisation

In normal network conditions, synchronisation information is carried by selected E1 or

T1 paths from upper to lower hierarchical levels according to the synchronisation plan,

from the MSC down to the BTSs.

Flexi EDGE BTS selects the E1 or T1 signal that has the highest priority from a group

of pre-selected digital paths as the active synchronisation signal. In case of FIQB/FIYB

PIU's PseudoWire Emulation (PWE)/PWE relay/Packet Abis over Ethernet/Packet Abis

over Ethernet relay will have ToP and 3 SyncE's ( SyncE (EIF1), Sync E (EIF2), SyncE

(EIF3) ). Among ToP, 3 SyncE's and 8 PseudoWires, only one source can be in the

priority list at a time. The operator can change the group of signals using the Flexi EDGE

BTS Manager application. Selection of a new signal is automatic in case of input failure

and input recovery.

In addition to using E1 or T1 signals for synchronisation, it is possible to synchronise

with an external clock signal, such as the LMU clock signal.

For PWE or PWE relay mode, the following external synchronization sources are available:











E1/T1's

Sync input, internal timing

2 MHz Clock

8 PseudoWires



In the PWE mode, the synchronization information can be forwarded via TDM IF 4 as

E1 signal.

For Packet Abis over TDM mode and in case of FIQB/FIYB PIU, the following external

synchronization sources are available:











E1/T1's

Sync input, internal timing

2 MHz Clock

ToP



For Packet Abis over Ethernet mode, the following external synchronization sources are

available:









E1/T1's

Sync input, internal timing

2 MHz Clock



For Packet Abis over Ethernet relay mode, the following external synchronization

sources are available:











E1/T1's

Sync input, internal timing

2 MHz Clock

8 PseudoWires



For PWE/PWE relay/Packet Abis over Ethernet/Packet Abis over Ethernet relay modes,

out of 4 E1/T1’s, only one can be in the priority list.

Network Synchronisation can be protected via PDH Loop Protection. See BSS30280

Abis loop protection for more details.



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Flexi EDGE BTS Feature Descriptions



8.1.5



Transmission equipment management

The management protocol for Nokia’s transmission equipment is Q1. The transmission

equipment can be external or internal to the BTS. The external equipment can be connected to the Flexi EDGE Base Station using a Q1 cable or a configured Q1 embedded

operations channel (EOC). In PseudoWire Emulation (PWE) mode, EOC configuration

is not supported in the BTS.

Either the base station controller (BSC) or Flexi EDGE Base Station can supervise the

transmission equipment. The Q1 protocol is a master/slave protocol. The master regularly polls the slaves. If the BSC is the master, the transmission equipment is said to be

under 'BSC polling'. If the Flexi EDGE BTS is the master, the transmission equipment is

said to be under 'BTS polling'. In PWE mode, the BTS does not support the BSC polling

because the EOC configuration is not supported. Note that the BSC polling can still be

configured for a BTS running in the PWE mode; the consequence is that transmission

alarms are not reported to the BSC, the BSC may also show an alarm that any polling

command sent via EOC configured in the BSC is not replied.

The alarms that the transmission equipment generates are transmitted to the BSC,

which further transfers them to Nokia NetAct.

If the BTS is the master, the BTS reports the transmission alarms to the BSC via the

OMUSIG channel.

If the BSC is the master, the BSC polls the alarms directly. A management channel must

be configured throughout the radio network between the BSC and the transmission

equipment. The management channel configuration at the BSC (service channel) must

match the configuration at the transmission equipment (embedded operations channel).

The BSC polling is only supported in the TDM/Packet Abis over TDM mode.

All equipment on the same channel must have a unique address (polling address) to

avoid conflicts. Only one master polls all transmission equipment. Loops are not

allowed, because Q1 is a bus protocol.

With Flexi EDGE BTS, it is not necessary to manually configure any Q1 switches to

establish the internal Q1 paths. The configuration is done automatically based on the Q1

polling mode. As a consequence, all internal or external transmission devices connected

to the BTS must be either BTS-polled or BSC-polled. A combination of polling modes is

not possible. This is important to keep in mind particularly when configuring the external

devices (which are connected to the BTS either via a Q1 cable or the EOC).

It is not possible to change the polling mode for the internal transmission equipment

manually at the Flexi EDGE BTS. It is the result of the configuration at the BSC. If the

Q1 polling mode is 'BSC Polling', the Q1 address value is read from the BSC (0-3999).

The Q1 address can be manually configured from the Flexi EDGE BTS Manager. This

should, however, be avoided to prevent conflicts.

With the Q1 Interface Handling BSC MML commands, the user creates the service

channels used in communication between the BSC and the transmission equipment.

The Q1 service channels are asynchronous serial communications channels. The

default maximum number of Q1 service channels in the BSC is 18. The user must define

every supervised equipment at the BSC. Altogether 512 pieces of equipment can be

defined into Q1 service channels under the BSC.

Supervision of transmission units supplied by other manufacturers

When transmission units supplied by other manufacturers are supervised via External

Alarm and Control (EAC) lines, the alarms can be sent to the BSC and NetAct. When



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Flexi EDGE BTS Feature Descriptions



the alarms are sent to the BSC and NetAct, the System Module (ESMA) supervises the

alarm handling, and alarms are reported as normal external alarms.



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Flexi EDGE BTS Feature Descriptions



8.1.6



Support for Nokia Microwave Radio Links

The FlexBus transmission sub-module (FIFA) forms the integrated microwave unit

support with Flexi EDGE BTS.

One FIFA transmission sub-module is used per Flexi EDGE BTS with two FlexBus interfaces, allowing for microwave radio tail and chain site topologies using Nokia FlexiHopper and MetroHopper.

The FIFA sub-module offers E1 bypass cross-connections from one FlexBus interface

to the other, and up to 16xE1 add/drop capability to Flexi EDGE BTS and sub 2M crossconnect function of which up to 8xE1 can be dropped to the BTS itself.

The FIFA sub-module is visible as a separate managed element at Nokia NetAct. The

operator can manage the FIFA sub-module locally and remotely using Nokia FlexiHub

manager. Flexi EDGE BTS provides functions for alarm, performance data polling and

forwarding to the BSC.

Some features related to Nokia Microwave Radio require an application SW licence, for

example the L55341.05 licence for an additional FlexBus interface.



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Flexi EDGE BTS Feature Descriptions



8.1.7



BSS9065 Transmission Operability

Flexi transmission equipment is measured with several counters:

















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All equipment can be measured within 15-minute/24-hour periods. This measurement gives a fixed set of counters, which are near-end G.826 signal quality counters.

These counters are:

• Total time

• Available time

• Errored seconds

• Severely errored seconds

• Background block errors

• Errored block

In the PWE mode, the following packet based counters are also available:

• Received Ethernet Packets

• Transmitted Ethernet Packets

• Ethernet Received Errored Packets

• Received PW packets in tunnel

• Transmitted PW packets in tunnel

• Packets not matching any PW*

• Number of PW packets lost

• Early Packets

• Late Packets

• Received PW packets with L bit set*

• Delay Variation Average

• Delay Variation Minimum

• Delay Variation Maximum

• Counters marked with a * are not reported to the BSC or NetAct

A certain set of Flexi transmission equipment can be defined. Flexi transmission

equipment refers either to the whole equipment or part of it (functional entity and

supervision block). It is also possible to define the counters that are collected from

the equipment. To do this, the topology of the transmission network must be known

so that the measurement subject can be chosen.

Packet Abis counters, for more detail see section Measurements and counters in the

Packet Abis feature descriptions document



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Flexi EDGE BTS Feature Descriptions



8.1.8



BSS21234 Support for BTS PWE Counters at BSC/NetAct

PseudoWire Emulation (PWE) provides the transparent transport of a TDM signal (E1

or T1) via a packet switched network (IP/Ethernet/UDP). The existing set of transmission alarms and counters was adapted to enable gathering performance data from BTS

at NetAct. This facilitates network performance analysis for troubleshooting and optimazation of packet switced network.



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Flexi EDGE BTS Feature Descriptions



8.1.9



BSS21290 Flexi EDGE Ethernet Switching

With Ethernet Switching on the Flexi EDGE plug-ins FIQx and FIYx it is possible to use

more the one Ethernet Interface; currently two FE’s and one GE are available. Thereby

external IP/Eth equipment/networks can be connected, such as DCN (Data Communication Network).



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