Контрольные задания

Задание №1.Абонентская цифровая сигнализация DSS-1. Форматы сообщений. Типы сообщений. Параметры сообщений. Расшифровка трейса протокола DSS-1.

Цель работы: Расшифровать трейс согласно формата 2 и 3 уровня сигнализации DSS-1.

1. Задание к работе:

Согласно варианта расшифровать протокол DSS-1 для стационарных сетей в формате протокола DSS-1 (для расшифровки используйте форматы 2 и 3 уровня, представленные в приложении 1)

Вариант 1. SETUP, Calling # 23974, Called # 14600

Layer 2 - Data Link Layer

Address field

00.......0EA0

......0.C/R = COMMAND

000000..SAPI = 0 Call control procedures

01.......1EA1

1100101.TEI = 01 Unautomatic assignment

Control field

0E.......0i Information

0001000.N(S) = 8

08.......0P

0000111.N(R) = 7

Layer 3 - Network Layer

08Protocol discriminator = Q.931

01....0001Call Reference Length = 1

020.......Flag = ORIGINATOR

.0000010Call Reference Value = 2

050.......E

.0000101Message type = SETUP

04Info Element = BEARER CAPABILITY

04Length = 4 octets

891.......EXT

.00.....Coding standard = CCITT

...01001Info transfer capability = restricted digital info

901.......EXT

.00.....Transfer mode = Circuit mode

...10000Info transfer rate = 64 kbit/s

210.......EXT

.01.....Layer 1 ID

...00001User info layer 1 protocol = CCITT V.110 & X.30

8F1.......EXT

.0......Synchronous/Asynchronous = Synchronous data

..0.....Negotiation = In-band negotiation not possible

...01111User rate = 56 kbit/s V.6

6CInfo Element = CALLING PARTY NUMBER

07Length = 7 octets

000.......EXT

.000....Type of number = Unknown

....0000Numbering plan = Unknown

801.......EXT

.00.....Presentation indicator = Presentation allowed

...000..Spare bit(s)

......00Screening indicator = User provided, not screened

32 33 39 37

34Number digits = 23974

70Info Element = CALLED PARTY NUMBER

06Length = 6 octets

811.......EXT

.000....Type of number = Unknown

....0001Numbering plan = ISDN/telephony numbering plan

31 34 36 30

30Number digits = 14600

Вариант 2 . SETUP ACKNOWLEDGE

Layer 2 - Data Link Layer

Address field

02.......0EA0

......1.C/R = COMMAND

000000..SAPI = 0 Call control procedures

CB.......1EA1

1100101.TEI = 101 Automatic assignment

Control field

00.......0I Information

0000000.N(S) = 0

02.......0P

0000001.N(R) = 1

Layer 3 - Network Layer

08Protocol discriminator = Q.931

01....0001Call Reference Length = 1

811.......Flag = DESTINATION

.0000001Call Reference Value = 1

0D0.......E

.0001101Message type = SETUP ACKNOWLEDGE

18Info Element = CHANNEL IDENTIFICATION

01Length = 1 octet

8A1.......EXT

.0......Interface identifier present = Interface implicitly

identified

..0.....Interface type = Basic

...0....Spare bit(s)

....1...Indicated channel = Exclusive

.....0..D-channel = False

......10Info channel = B2 channel

Вариант 3. INFORMATION, Called # 1

Layer 2 - Data Link Layer

Address field

00.......0EA0

......0.C/R = COMMAND

000000..SAPI = 0 Call control procedures

CB.......1EA1

1100101.TEI = 101 Automatic assignment

Control field