SS7 - Signaling System No. 7 (2G/3G)

What is SS7?

• SS7 (Signaling System No. 7) is a set of telephony signaling protocols used to set up and tear down telephone calls, manage mobile services, and support features like SMS, number translation, and prepaid billing. It is used in traditional circuit-switched telephone networks (PSTN) and mobile networks (2G/3G).

• SS7 enables communication between network elements like switches, databases (e.g., HLR, VLR), and service control points (SCPs).

Why is SS7 useful?

• SS7 is critical in legacy and mobile telecom infrastructure because: * Call setup and teardown – Establishes and ends voice calls across networks. * Mobile roaming – Supports location updates and handovers between networks. * SMS delivery – Transports text messages between mobile devices. * Number translation – Enables services like toll-free numbers and call forwarding. * Billing and prepaid services – Supports real-time charging and account management. * Network management – Provides signaling for congestion control, fault detection, and routing.

How it works?

• Call Initiation – A user dials a number; the local exchange sends a signaling message via SS7.

• Routing and Translation – SS7 queries databases (like HLR or SCP) to resolve the destination or service logic.

• Call Setup – The call is routed through the network using ISUP (ISDN User Part) messages.

• Call Management – SS7 handles call progress, status updates, and supplementary services.

• Call Termination – When the call ends, SS7 tears down the connection and updates billing systems.

Where is SS7 used?

• Public Switched Telephone Network (PSTN) – For call control and routing.

• Mobile networks (2G/3G) – For roaming, SMS, and subscriber management.

• SMS Centers (SMSC) – For delivering and routing text messages.

• Intelligent Network (IN) services – Like toll-free numbers, call forwarding, and prepaid billing.

• Mobile Number Portability (MNP) – For querying number databases.

• Lawful Interception – Used by governments for surveillance and monitoring.

Which OSI layer does SS7 belong to?

• SS7 spans multiple layers of the OSI model, but its core signaling functions are implemented at the Network Layer (Layer 3). Here’s why:

• Message Routing: SS7 uses the Message Transfer Part (MTP) and Signaling Connection Control Part (SCCP) for reliable message delivery and routing, which are Layer 3 functions.

• Addressing and Switching: It handles global title translation and point code addressing, similar to IP routing.

• Reliable Transport: While MTP Level 2 ensures reliable delivery (like Layer 2), the core logic of SS7 signaling resides in Layer 3.

• Protocol Stack: SS7 has its own layered architecture (MTP1–3, SCCP, TCAP, ISUP, MAP), which maps roughly to OSI Layers 1–4, with Layer 3 being the most central for signaling logic.

Topics in this section,

• Learnings in this section

• Terminology

• Version Info

• SS7 Version&RFC Details

• SS7 Basic Setup on Ubuntu using IPv4

• SS7 Basic Setup on Ubuntu using IPv6

• SS7 Protocol Packet Details

• SS7 Usecases

• SS7 Basic Features

• SS7 Feature : Out-of-Band Signaling

• SS7 Feature : Reliable Message Transfer

• SS7 Feature : Global Title Translation

• SS7 Feature : Fast Call Setup

• SS7 Feature : Network Management

• SS7 Feature : Support for Mobile Services

• SS7 Feature : Scalability

• SS7 Feature : Interoperability

• SS7 Feature : Security (Basic)

• ref:

  SS7 Feature : Service Flexibility <SS7_step18>

• Reference links

Learnings in this section

• In this section, you are going to learn

Terminology

• Terminology

Version Info

• Version Info

SS7 Version&RFC Details

SS7 Version	SS7 Number	Year	Core Idea / Contribution
SS7 Introduction	ITU-T Q.700	1988	Defined the architecture and overview of SS7 signaling system.
MTP Level 13	ITU-T Q.701Q.705	1988	Physical, data link, and network layers for reliable message transfer and routing.
SCCP	ITU-T Q.711Q.714	1988	Provides extended routing, segmentation, and global title translation.
TCAP	ITU-T Q.771Q.775	1993	Enables transaction-based communication for services like number translation, SMS, etc.
ISUP	ITU-T Q.761Q.764	1988	Handles call setup, management, and teardown in circuit-switched networks.
MAP	3GPP TS 09.02	1990s	Mobile-specific signaling for roaming, authentication, SMS, etc.
SIGTRAN (SS7 over IP)	RFC 4960 (SCTP), RFC 4666 (M3UA), RFC 3868 (SUA), etc.	2000s	Transports SS7 signaling over IP networks using SCTP.

SS7 Basic Setup on Ubuntu using IPv4

• Setup

SS7 Basic Setup on Ubuntu using IPv6

• Setup

SS7 Protocol Packet Details

MTP Level 2 Packet

MTP Level 3 Packet

SCCP Packet

TCAP Packet

ISUP Packet

MAP Packet

SS7 Usecases

S.no	Use Case	Description
1	Call Setup and Teardown	Establishes and terminates voice calls in circuit-switched networks.
2	Mobile Roaming	Enables users to access services while roaming by updating location info.
3	SMS Delivery	Facilitates sending and receiving SMS messages via MAP and TCAP layers.
4	Number Portability	Supports querying databases to route calls to ported numbers.
5	Prepaid Billing	Enables real-time balance checks and call control for prepaid users.
6	Caller ID and CLIP/CLIR	Provides calling line identification and restriction services.
7	Toll-Free Number Translation	Translates toll-free numbers to routable geographic numbers.
8	Lawful Interception	Allows authorized agencies to monitor communications for legal purposes.
9	Location-Based Services	Provides user location data for emergency services or commercial apps.
10	Fraud Detection & Prevention	Monitors signaling patterns to detect and prevent telecom fraud.

SS7 Basic Features

S.no	Feature	Description
1	Out-of-Band Signaling	Uses a separate channel for signaling, independent of the voice/data path.
2	Reliable Message Transfer	Ensures error-free delivery using MTP Level 2 with retransmission and CRC.
3	Global Title Translation	Allows routing based on logical addresses like phone numbers.
4	Fast Call Setup	Enables rapid call establishment compared to earlier in-band signaling.
5	Network Management	Supports rerouting and load sharing in case of congestion or failure.
6	Support for Mobile Services	Enables roaming, SMS, authentication, and location updates in mobile networks.
7	Scalability	Can support large networks with millions of subscribers and signaling points.
8	Interoperability	Works across different vendors and network types (PSTN, GSM, UMTS).
9	Security (Basic)	Includes basic signaling integrity checks, though modern networks need more.
10	Service Flexibility	Supports a wide range of services like toll-free calls, prepaid billing, etc.

SS7 Feature : Out-of-Band Signaling

Out-of-Band Signaling - Testcases

#	Test Case	Description	Expected Result
1	Signaling Channel Isolation	Ensure signaling uses a separate channel from voice/data	Signaling isolated from payload
2	Unauthorized Access Attempt	Attempt access to signaling channel	Access denied
3	Signaling Channel Encryption	Encrypt signaling messages	Messages encrypted end-to-end
4	Replay Attack on Signaling	Replay captured signaling messages	Attack detected and blocked
5	Signaling Integrity Check	Modify signaling message in transit	Integrity check fails
6	Signaling Authentication	Authenticate signaling endpoints	Only trusted nodes accepted
7	Signaling Firewall Rules	Apply firewall rules to signaling channel	Unauthorized traffic blocked
8	Signaling Rate Limiting	Flood signaling channel	Excess traffic throttled
9	Signaling Channel Monitoring	Monitor signaling traffic	Anomalies logged and alerted
10	Signaling Channel Logging	Log signaling events	Logs contain full trace
11	Signaling Channel Redundancy	Failover to backup signaling link	Seamless failover
12	Signaling Channel Tampering	Inject malformed signaling packets	Packets rejected
13	Signaling Node Authentication	Verify node identity	Only authenticated nodes allowed
14	Signaling Message Validation	Validate message format and content	Invalid messages rejected
15	Signaling Channel Encryption Key Rotation	Rotate encryption keys periodically	Keys updated without disruption
16	Signaling Channel Replay Detection	Detect duplicate messages	Duplicates flagged
17	Signaling Channel DoS Protection	Simulate DoS attack	Attack mitigated
18	Signaling Channel Access Control	Restrict access by IP or ID	Unauthorized sources blocked
19	Signaling Channel Packet Inspection	Deep packet inspection of signaling	Malicious content detected
20	Signaling Channel Anomaly Detection	Use AI/ML to detect anomalies	Suspicious behavior flagged
21	Signaling Channel Session Timeout	Idle session timeout	Session closed after inactivity
22	Signaling Channel Encryption Algorithm Test	Use strong encryption (e.g., AES-256)	Encryption successful
23	Signaling Channel Certificate Validation	Validate certificates used	Only valid certs accepted
24	Signaling Channel Certificate Revocation	Use revoked cert	Connection rejected
25	Signaling Channel Mutual TLS	Use mTLS for signaling	Both ends authenticated
26	Signaling Channel with VPN	Tunnel signaling over VPN	Traffic encrypted and isolated
27	Signaling Channel with IPsec	Use IPsec for signaling	Secure tunnel established
28	Signaling Channel with MAC Filtering	Allow only specific MACs	Unauthorized MACs blocked
29	Signaling Channel with Geo-Fencing	Restrict signaling by region	Out-of-region access denied
30	Signaling Channel with Time-Based Access	Allow signaling only during hours	Off-hour access blocked
31	Signaling Channel with Role-Based Access	Different roles for access	Access based on role
32	Signaling Channel with Audit Trail	Maintain audit logs	All actions logged
33	Signaling Channel with Alerting	Alert on suspicious activity	Alerts triggered
34	Signaling Channel with Redundancy Test	Simulate link failure	Backup link activated
35	Signaling Channel with Load Balancing	Distribute signaling load	Load evenly distributed
36	Signaling Channel with Packet Loss	Simulate packet loss	Retransmission or failover
37	Signaling Channel with Latency Test	Measure latency	Within acceptable limits
38	Signaling Channel with Jitter Test	Measure jitter	Within acceptable limits
39	Signaling Channel with Bandwidth Throttling	Limit bandwidth	Signaling adapts
40	Signaling Channel with QoS	Apply QoS policies	Prioritized signaling traffic
41	Signaling Channel with NAT Traversal	Traverse NAT devices	Signaling successful
42	Signaling Channel with IPv6	Use IPv6 for signaling	Signaling works over IPv6
43	Signaling Channel with IPv4	Use IPv4 for signaling	Signaling works over IPv4
44	Signaling Channel with Mixed IP	Use dual-stack IP	Signaling works in both
45	Signaling Channel with Protocol Downgrade	Attempt downgrade attack	Downgrade blocked
46	Signaling Channel with Protocol Upgrade	Upgrade to newer protocol	Upgrade successful
47	Signaling Channel with Compression	Compress signaling messages	Messages compressed and delivered
48	Signaling Channel with Fragmentation	Send fragmented messages	Reassembled correctly
49	Signaling Channel with Congestion	Simulate network congestion	Signaling remains functional
50	Signaling Channel with End-to-End Encryption	Encrypt from source to destination	Only endpoints can decrypt

SS7 Feature : Reliable Message Transfer

Reliable Message Transfer - Testcases

#	Test Case	Description	Expected Result
1	CRC Validation	Send message with correct CRC	Message accepted
2	CRC Tampering	Modify CRC value	Message rejected
3	Retransmission on NACK	Simulate NACK response	Message retransmitted
4	Retransmission Timeout	Delay ACK beyond timeout	Retransmission triggered
5	Duplicate Message Detection	Send same message twice	Duplicate discarded
6	Sequence Number Validation	Send out-of-order messages	Out-of-order detected
7	Message Loss Simulation	Drop message in transit	Retransmission occurs
8	Bit Error Injection	Flip bits in message	CRC detects error
9	Frame Length Validation	Send malformed frame	Frame rejected
10	Buffer Overflow Attempt	Send oversized message	Buffer protected
11	Message Flooding	Send rapid messages	Throttling or drop
12	ACK Spoofing	Spoof ACK from attacker	Ignored or flagged
13	NACK Spoofing	Spoof NACK to trigger resend	Detected and ignored
14	Retransmission Limit	Exceed max retries	Message dropped
15	CRC Algorithm Test	Use different CRC algorithms	Correct one validated
16	Message Delay Simulation	Introduce delay	Retransmission logic handles it
17	Link Congestion Handling	Simulate congestion	Messages queued or rerouted
18	Link Failure Recovery	Break and restore link	Messages retransmitted
19	Sequence Number Wraparound	Reach max sequence number	Wraparound handled
20	Message Fragmentation	Send fragmented messages	Reassembled correctly
21	Message Reassembly Attack	Send mismatched fragments	Reassembly fails
22	Message Replay Attack	Replay old message	Detected and discarded
23	Message Injection	Inject unauthorized message	Rejected by validation
24	Message Integrity Check	Alter message content	CRC fails
25	Message Authentication	Authenticate sender	Only valid sources accepted
26	Link Layer Encryption	Encrypt MTP2 messages	Decrypted and validated
27	Link Layer Tampering	Modify encrypted message	Decryption or CRC fails
28	Link Layer Logging	Log all MTP2 events	Complete trace available
29	Link Layer Monitoring	Monitor for anomalies	Alerts triggered
30	Link Layer Redundancy	Use backup link	Failover successful
31	Link Layer Load Balancing	Distribute load	Balanced traffic
32	Link Layer DoS Protection	Simulate DoS	Attack mitigated
33	Link Layer Access Control	Restrict access	Unauthorized blocked
34	Link Layer Authentication	Authenticate link endpoints	Only trusted links allowed
35	Link Layer Session Timeout	Idle timeout	Session closed
36	Link Layer Key Rotation	Rotate encryption keys	Secure transition
37	Link Layer Replay Window	Use sliding window	Replays outside window rejected
38	Link Layer Sequence Gaps	Skip sequence numbers	Gaps detected
39	Link Layer Heartbeat	Send keep-alive	Link status confirmed
40	Link Layer Error Rate Threshold	Exceed error threshold	Link flagged or reset
41	Link Layer Protocol Downgrade	Attempt downgrade	Downgrade blocked
42	Link Layer Protocol Upgrade	Upgrade protocol version	Upgrade successful
43	Link Layer with VPN	Tunnel MTP2 over VPN	Secure and reliable
44	Link Layer with IPsec	Use IPsec for transport	Encrypted and authenticated
45	Link Layer with NAT	Traverse NAT	Signaling successful
46	Link Layer with IPv6	Use IPv6 transport	Reliable delivery
47	Link Layer with IPv4	Use IPv4 transport	Reliable delivery
48	Link Layer with Mixed IP	Dual-stack support	Both IP versions supported
49	Link Layer with Compression	Compress messages	Delivered and decompressed
50	Link Layer with Congestion Control	Simulate congestion	Flow controlled

SS7 Feature : Global Title Translation

Global Title Translation - Testcases

#	Test Case	Description	Expected Result
1	Valid Global Title Translation	Translate valid GT	Correct destination routed
2	Invalid Global Title Format	Use malformed GT	Translation fails
3	Unauthorized GT Access	Attempt access to GT database	Access denied
4	GT Spoofing Attempt	Use spoofed GT	Detected and blocked
5	GT Translation Logging	Log translation events	Logs contain full trace
6	GT Translation Monitoring	Monitor GT traffic	Anomalies flagged
7	GT Translation with Encryption	Encrypt GT data	Data decrypted securely
8	GT Translation with Tampered Data	Modify GT in transit	Translation fails
9	GT Translation with Replay Attack	Replay GT request	Detected and rejected
10	GT Translation with Rate Limiting	Flood GT requests	Excess requests throttled
11	GT Translation with Access Control	Restrict GT access	Unauthorized blocked
12	GT Translation with Role-Based Access	Access based on role	Role policies enforced
13	GT Translation with Redundancy	Use backup GT database	Failover successful
14	GT Translation with Load Balancing	Distribute GT queries	Balanced load
15	GT Translation with Timeout	Delay response	Timeout triggered
16	GT Translation with Logging Policy	Enforce logging rules	Logs comply with policy
17	GT Translation with Alerting	Alert on suspicious GT	Alerts triggered
18	GT Translation with NAT Traversal	Translate GT behind NAT	Routing successful
19	GT Translation with IPv6	Use IPv6 GT routing	Translation successful
20	GT Translation with IPv4	Use IPv4 GT routing	Translation successful
21	GT Translation with Mixed IP	Dual-stack GT routing	Both IPs supported
22	GT Translation with Protocol Downgrade	Attempt downgrade	Downgrade blocked
23	GT Translation with Protocol Upgrade	Upgrade translation protocol	Upgrade successful
24	GT Translation with DNS Resolution	Resolve GT via DNS	Correct address returned
25	GT Translation with Database Integrity	Corrupt GT database	Integrity check fails
26	GT Translation with Database Encryption	Encrypt GT database	Data protected
27	GT Translation with Database Backup	Restore from backup	Translation resumes
28	GT Translation with Database Tampering	Modify GT entries	Tampering detected
29	GT Translation with Certificate Validation	Validate certs used	Only valid certs accepted
30	GT Translation with Certificate Revocation	Use revoked cert	Translation blocked
31	GT Translation with Mutual TLS	Use mTLS for GT access	Both ends authenticated
32	GT Translation with VPN	Tunnel GT access	Secure and isolated
33	GT Translation with IPsec	Use IPsec for GT routing	Encrypted and authenticated
34	GT Translation with Firewall Rules	Apply firewall to GT access	Unauthorized blocked
35	GT Translation with Anomaly Detection	Use ML to detect anomalies	Suspicious GT flagged
36	GT Translation with Replay Window	Use sliding window	Replays outside window rejected
37	GT Translation with Sequence Validation	Validate GT sequence	Invalid sequence rejected
38	GT Translation with Heartbeat	Send keep-alive	GT service confirmed
39	GT Translation with Error Rate Threshold	Exceed error threshold	GT service flagged
40	GT Translation with Compression	Compress GT data	Delivered and decompressed
41	GT Translation with Fragmentation	Send fragmented GT data	Reassembled correctly
42	GT Translation with Congestion Control	Simulate congestion	Flow controlled
43	GT Translation with Logging Retention	Retain logs per policy	Logs archived
44	GT Translation with Audit Trail	Maintain audit logs	All actions traceable
45	GT Translation with Policy Enforcement	Enforce GT access policy	Policy applied
46	GT Translation with Signature Validation	Validate signed GT request	Signature verified
47	GT Translation with Invalid Signature	Tamper with signature	Request rejected
48	GT Translation with Timestamp Validation	Validate GT timestamp	Time verified
49	GT Translation with End-to-End Encryption	Encrypt GT request	Only endpoints can decrypt
50	GT Translation with Proxy Forwarding	Forward GT via proxy	Translation preserved

SS7 Feature : Fast Call Setup

Fast Call Setup - Testcases

#	Test Case	Description	Expected Result
1	Valid Call Setup	Initiate call with valid parameters	Call established quickly
2	Invalid Call Setup Request	Use malformed setup message	Call rejected
3	Call Setup with Spoofed Caller ID	Use fake caller ID	Detected and blocked
4	Call Setup with Encryption	Encrypt signaling messages	Call setup secured
5	Call Setup with Replay Attack	Replay previous setup message	Rejected as duplicate
6	Call Setup with Tampered Message	Modify setup message in transit	Integrity check fails
7	Call Setup with Authentication	Authenticate signaling endpoints	Only trusted nodes allowed
8	Call Setup with Rate Limiting	Flood setup requests	Excess requests throttled
9	Call Setup with Logging	Log call setup events	Logs contain full trace
10	Call Setup with Monitoring	Monitor setup traffic	Anomalies flagged
11	Call Setup with Redundancy	Use backup signaling path	Call setup succeeds
12	Call Setup with Load Balancing	Distribute setup load	Balanced and fast setup
13	Call Setup with Timeout	Delay response	Setup times out
14	Call Setup with NAT Traversal	Setup call across NAT	Call established
15	Call Setup with IPv6	Use IPv6 signaling	Call setup successful
16	Call Setup with IPv4	Use IPv4 signaling	Call setup successful
17	Call Setup with Mixed IP	Dual-stack signaling	Both IPs supported
18	Call Setup with Protocol Downgrade	Attempt downgrade	Downgrade blocked
19	Call Setup with Protocol Upgrade	Upgrade signaling protocol	Upgrade successful
20	Call Setup with Firewall Rules	Apply firewall to signaling	Unauthorized blocked
21	Call Setup with Certificate Validation	Use valid certs	Setup trusted
22	Call Setup with Certificate Revocation	Use revoked cert	Setup rejected
23	Call Setup with Mutual TLS	Use mTLS for signaling	Both ends authenticated
24	Call Setup with VPN	Tunnel signaling	Setup encrypted and isolated
25	Call Setup with IPsec	Use IPsec for signaling	Setup secured
26	Call Setup with Anomaly Detection	Use ML to detect anomalies	Suspicious setup flagged
27	Call Setup with Replay Window	Use sliding window	Replays outside window rejected
28	Call Setup with Sequence Validation	Validate message sequence	Invalid sequence rejected
29	Call Setup with Heartbeat	Send keep-alive before setup	Link status confirmed
30	Call Setup with Error Rate Threshold	Exceed error threshold	Setup flagged or blocked
31	Call Setup with Compression	Compress signaling	Setup succeeds
32	Call Setup with Fragmentation	Send fragmented setup message	Reassembled correctly
33	Call Setup with Congestion Control	Simulate congestion	Setup adapts
34	Call Setup with Logging Retention	Retain logs per policy	Logs archived
35	Call Setup with Audit Trail	Maintain audit logs	All actions traceable
36	Call Setup with Policy Enforcement	Enforce setup policy	Policy applied
37	Call Setup with Signature Validation	Validate signed setup	Signature verified
38	Call Setup with Invalid Signature	Tamper with signature	Setup rejected
39	Call Setup with Timestamp Validation	Validate timestamp	Time verified
40	Call Setup with End-to-End Encryption	Encrypt from source to destination	Only endpoints can decrypt
41	Call Setup with Proxy Forwarding	Forward setup via proxy	Setup preserved
42	Call Setup with SIP Interworking	Interwork with SIP	Setup successful
43	Call Setup with ISUP Interworking	Interwork with ISUP	Setup successful
44	Call Setup with MAP Interworking	Interwork with MAP	Setup successful
45	Call Setup with CAMEL Interworking	Interwork with CAMEL	Setup successful
46	Call Setup with Location-Based Routing	Route based on location	Correct destination
47	Call Setup with Number Portability	Handle ported numbers	Correct routing
48	Call Setup with GT Translation	Use GT for routing	Setup successful
49	Call Setup with Load Spike	Simulate traffic spike	Setup remains fast
50	Call Setup with Link Failure	Break signaling link	Setup rerouted or retried

SS7 Feature : Network Management

Network Management - Testcases

#	Test Case	Description	Expected Result
1	Normal Routing	Send message with no congestion	Routed via primary path
2	Primary Route Congestion	Simulate congestion on primary route	Message rerouted to alternate
3	Primary Route Failure	Simulate failure on primary route	Message rerouted to backup
4	All Routes Congested	Simulate congestion on all routes	Message queued or dropped
5	Load Sharing Enabled	Enable load sharing	Traffic distributed across routes
6	Load Sharing with Weights	Assign weights to routes	Traffic follows weight distribution
7	Route Recovery	Recover failed route	Traffic resumes on recovered route
8	Congestion Cleared	Clear congestion on primary	Traffic returns to primary
9	Route Preference Change	Change route preference	Preferred route used
10	Route Cost Update	Update cost metrics	Routing reflects new cost
11	Route Blacklisting	Blacklist a route	Route not used
12	Route Whitelisting	Whitelist a route	Route preferred
13	Route Timeout	Simulate timeout	Alternate route used
14	Route Delay Simulation	Introduce delay	Delay logged, alternate used
15	Route Jitter Simulation	Simulate jitter	Route monitored, rerouted if unstable
16	Route Packet Loss	Simulate packet loss	Route avoided if threshold exceeded
17	Route Error Rate	Simulate high error rate	Route avoided
18	Route Bandwidth Limit	Limit bandwidth	Load shared to meet bandwidth
19	Route Latency Limit	Set latency threshold	Alternate used if exceeded
20	Route Maintenance Mode	Put route under maintenance	Route avoided
21	Route Under Test	Mark route as test-only	Not used in production
22	Route Overload	Simulate overload	Load shared or rerouted
23	Route Authentication Failure	Fail route authentication	Route rejected
24	Route Encryption Failure	Fail encryption	Message dropped or rerouted
25	Route Integrity Check Fail	Fail integrity check	Message dropped
26	Congestion Alert Triggered	Trigger congestion alert	Load shared or rerouted
27	Failover Test	Test failover mechanism	Backup route used
28	Fallback Test	Test fallback mechanism	Fallback route used
29	Policy Enforcement	Apply routing policy	Policy enforced
30	Priority Change	Change route priority	Priority respected
31	Route Aging	Simulate aging	Aged route removed
32	Route Refresh	Refresh route table	Updated routes used
33	Cache Hit	Use cached route	Cached route used
34	Cache Miss	Miss in cache	Route resolved dynamically
35	Loop Detection	Simulate routing loop	Loop detected and broken
36	TTL Expiry	Exceed TTL	Message dropped
37	Metrics Update	Update route metrics	Routing adapts
38	Load Spike	Simulate traffic spike	Load balanced
39	Link Failure	Break route link	Message rerouted
40	Link Recovery	Restore broken link	Route resumes use
41	Congestion Threshold Exceeded	Exceed threshold	Alert triggered
42	Monitoring Enabled	Enable monitoring	Anomalies flagged
43	Logging Enabled	Enable logging	Logs contain full trace
44	Alerting Enabled	Enable alerts	Alerts triggered
45	NAT Traversal	Route behind NAT	Routing successful
46	IPv6 Support	Use IPv6 route	Routing successful
47	IPv4 Support	Use IPv4 route	Routing successful
48	Dual Stack Routing	Use dual-stack route	Both IPs supported
49	Signature Validation	Validate route signature	Signature verified
50	Timestamp Validation	Validate timestamp	Time verified

SS7 Feature : Support for Mobile Services

Support for Mobile Services - Testcases

#	Test Case	Description	Expected Result
1	Successful Roaming Registration	Register roaming subscriber	Roaming allowed
2	Invalid IMSI in Roaming	Use malformed IMSI	Registration rejected
3	Roaming with Unauthorized Network	Attempt to roam on unauthorized PLMN	Access denied
4	Roaming with Blacklisted SIM	Use blacklisted SIM	Registration blocked
5	Roaming with Expired Subscription	Use expired account	Roaming denied
6	Roaming Location Update	Move to new VLR area	Location updated
7	Roaming with Congested VLR	Simulate VLR congestion	Retry or alternate VLR used
8	Roaming with Delayed Response	Delay in VLR response	Timeout or retry triggered
9	Roaming with Authentication Failure	Fail authentication	Roaming denied
10	Roaming with Successful Authentication	Authenticate subscriber	Roaming allowed
11	SMS Delivery in Home Network	Send SMS from home network	SMS delivered
12	SMS Delivery in Roaming	Send SMS while roaming	SMS delivered
13	SMS to Invalid Number	Send SMS to invalid MSISDN	Delivery failed
14	SMS with Spoofed Origin	Send SMS with fake sender	Message blocked
15	SMS with Congested SMSC	Simulate SMSC congestion	Message queued or delayed
16	SMS with Delivery Report	Request delivery report	Report received
17	SMS with No Delivery Report	Disable delivery report	No report received
18	SMS with Invalid Format	Send malformed SMS	Message rejected
19	SMS with Long Message	Send multipart SMS	Message reassembled correctly
20	SMS with Unicode Characters	Send SMS with Unicode	Message delivered correctly
21	Authentication with Valid Credentials	Authenticate with correct IMSI/Ki	Authentication successful
22	Authentication with Invalid Ki	Use wrong key	Authentication failed
23	Authentication with Replay Attack	Replay authentication request	Request rejected
24	Authentication with Tampered RAND	Modify RAND value	Authentication fails
25	Authentication with Delayed Response	Delay in response from HLR	Timeout triggered
26	Authentication with Multiple Attempts	Retry after failure	Limited retries allowed
27	Authentication with Roaming	Authenticate in visited network	Authentication successful
28	Authentication with Home Network	Authenticate in home network	Authentication successful
29	Location Update in Home Network	Move within home network	Location updated
30	Location Update in Roaming	Move to new VLR while roaming	Location updated
31	Location Update with Invalid IMSI	Use invalid IMSI	Update rejected
32	Location Update with Congested HLR	Simulate HLR congestion	Retry or delay
33	Location Update with VLR Failure	VLR not responding	Alternate VLR used
34	Location Update with Delayed Response	Delay in update	Timeout or retry
35	Location Update with Authentication	Require authentication	Update allowed after auth
36	Location Update with No Authentication	Skip authentication	Update denied
37	Location Update with SIM Swap	Change SIM in device	Update processed
38	Location Update with IMSI Attach	Attach with IMSI	Location updated
39	Location Update with TMSI Reallocation	Reallocate TMSI	New TMSI assigned
40	Location Update with Invalid TMSI	Use invalid TMSI	Update rejected
41	Roaming with CAMEL Support	Use CAMEL services while roaming	Services available
42	Roaming with No CAMEL Support	No CAMEL in visited network	Limited services
43	SMS with MAP Protocol	Use MAP for SMS routing	Message delivered
44	SMS with SCCP Failure	Fail SCCP routing	Message undelivered
45	Authentication with MAP Protocol	Use MAP for auth	Auth successful
46	Location Update with MAP Protocol	Use MAP for update	Update successful
47	SMS with MT Forwarding	Forward MT SMS	Message delivered
48	SMS with MO Forwarding	Forward MO SMS	Message delivered
49	Roaming with Number Portability	Roam with ported number	Routing successful
50	Roaming with IMSI Detach	Detach from network	Roaming session ended

SS7 Feature : Scalability

Scalability - Testcases

#	Test Case	Description	Expected Result
1	High Subscriber Volume	Simulate 1 million subscribers	System handles load
2	High Signaling Point Count	Add 10,000 signaling points	All points reachable
3	Concurrent SMS Traffic	Send 100,000 SMS simultaneously	All messages processed
4	Concurrent Call Setup	Initiate 50,000 calls	Calls established successfully
5	Location Updates at Scale	Trigger 500,000 updates	Updates processed
6	Authentication at Scale	Authenticate 1 million users	Auth successful
7	Roaming at Scale	Register 100,000 roamers	Roaming allowed
8	Load Balancing Across STPs	Distribute traffic across STPs	Balanced load
9	STP Overload Handling	Overload one STP	Traffic rerouted
10	HLR Query Load	Send 200,000 queries	All queries answered
11	VLR Load Test	Simulate 100,000 VLR entries	VLR responds correctly
12	MSC Load Test	Simulate 50,000 call setups	MSC handles load
13	SCCP Routing at Scale	Route 1 million SCCP messages	All routed correctly
14	MAP Transactions at Scale	Process 500,000 MAP requests	All processed
15	TCAP Dialogs at Scale	Open 100,000 dialogs	Dialogs maintained
16	GTT at Scale	Translate 1 million GTs	All translated
17	Congestion Control at Scale	Simulate network congestion	Traffic managed
18	Database Replication	Replicate large HLR/VLR	Replication successful
19	Backup and Restore	Backup 1 million records	Restore successful
20	Real-Time Monitoring	Monitor 1 million events	No delay in alerts
21	Logging at Scale	Log 10 million events	Logs complete
22	Alerting at Scale	Trigger 100,000 alerts	All alerts received
23	Routing Table Size	Load large routing table	Routes resolved
24	Dynamic Route Updates	Update 10,000 routes	Updates applied
25	Failover at Scale	Fail 1,000 nodes	Traffic rerouted
26	Redundancy Test	Simulate node failure	Redundant node takes over
27	Load Spike Handling	Sudden traffic spike	System remains stable
28	Memory Usage Under Load	Monitor memory with 1M users	Within limits
29	CPU Usage Under Load	Monitor CPU with 1M users	Within limits
30	Disk I/O Under Load	Monitor disk access	No bottlenecks
31	Network Latency at Scale	Measure latency	Within acceptable range
32	Packet Loss at Scale	Simulate traffic loss	Retransmission successful
33	Throughput Measurement	Measure throughput	Meets expected rate
34	Session Management	Manage 1 million sessions	All sessions stable
35	Timer Management	Handle 1 million timers	No timer failures
36	Queue Management	Manage message queues	No overflow
37	Resource Allocation	Allocate resources dynamically	No resource starvation
38	Multi-Vendor Interop	Interoperate with other vendors	Seamless communication
39	Multi-Region Support	Deploy across regions	All regions connected
40	Load Distribution by Geography	Distribute load by region	Balanced traffic
41	Multi-Operator Support	Support multiple operators	No conflicts
42	Multi-PLMN Support	Handle multiple PLMNs	All PLMNs reachable
43	Multi-IMSI Support	Handle multiple IMSIs per user	All IMSIs processed
44	Multi-SIM Devices	Support dual SIM devices	Both SIMs functional
45	Multi-Protocol Support	Handle MAP, ISUP, CAP	All protocols supported
46	Multi-Technology Support	Support 2G/3G/4G/5G	All technologies functional
47	Horizontal Scaling	Add more nodes	System scales linearly
48	Vertical Scaling	Increase node capacity	Performance improves
49	Auto-Scaling	Scale based on load	Resources added dynamically
50	Stress Test	Push system to limits	No crash or data loss

SS7 Feature : Interoperability

Interoperability - Testcases

#	Test Case	Description	Expected Result
1	GSM to UMTS Call Setup	Initiate call from GSM to UMTS	Call established
2	UMTS to GSM Call Setup	Initiate call from UMTS to GSM	Call established
3	GSM to PSTN Call	Call from GSM to landline	Call connected
4	PSTN to GSM Call	Call from landline to GSM	Call connected
5	UMTS to PSTN Call	Call from UMTS to PSTN	Call connected
6	PSTN to UMTS Call	Call from PSTN to UMTS	Call connected
7	SMS from GSM to UMTS	Send SMS from GSM to UMTS	SMS delivered
8	SMS from UMTS to GSM	Send SMS from UMTS to GSM	SMS delivered
9	SMS from GSM to PSTN	Send SMS to landline	Converted or rejected
10	SMS from PSTN to GSM	Receive SMS from landline	Delivered or rejected
11	Roaming between GSM and UMTS	Roam from GSM to UMTS	Roaming successful
12	Roaming between UMTS and GSM	Roam from UMTS to GSM	Roaming successful
13	Authentication across vendors	Authenticate on different vendor MSC	Auth successful
14	Location update across networks	Update location from GSM to UMTS	Update successful
15	Inter-vendor MAP message	Send MAP message between vendors	Message processed
16	Inter-vendor SCCP routing	Route SCCP between vendors	Routing successful
17	Inter-vendor TCAP dialog	Establish TCAP dialog	Dialog maintained
18	Inter-vendor ISUP call setup	Setup call using ISUP	Call established
19	Inter-vendor CAMEL support	Use CAMEL services across vendors	Services available
20	Inter-vendor HLR access	Query HLR from different vendor	Query successful
21	Inter-vendor VLR access	Query VLR from different vendor	Query successful
22	Inter-vendor MSC handover	Handover between MSCs	Seamless transition
23	Inter-vendor STP routing	Route via different vendor STP	Routing successful
24	Inter-vendor congestion handling	Handle congestion across vendors	Load shared
25	Inter-vendor error handling	Handle protocol errors	Errors managed
26	Inter-vendor protocol versioning	Use different MAP versions	Compatible communication
27	Inter-vendor timer management	Sync timers across vendors	No timeout issues
28	Inter-vendor GTT	Translate GT across vendors	Routing successful
29	Inter-vendor number portability	Route ported numbers	Correct destination
30	Inter-vendor NAT traversal	Traverse NAT between networks	Communication successful
31	Inter-vendor encryption	Use encryption across vendors	Data secured
32	Inter-vendor authentication failure	Fail auth on foreign MSC	Access denied
33	Inter-vendor fallback	Fallback to alternate vendor	Service continuity
34	Inter-vendor redundancy	Use backup vendor node	Failover successful
35	Inter-vendor alerting	Trigger alerts across vendors	Alerts received
36	Inter-vendor logging	Log events across vendors	Logs complete
37	Inter-vendor monitoring	Monitor traffic across vendors	Anomalies flagged
38	Inter-vendor policy enforcement	Enforce policies across vendors	Policies applied
39	Inter-vendor firewall traversal	Traverse firewalls	Communication allowed
40	Inter-vendor protocol mismatch	Use different protocol versions	Compatibility maintained
41	Inter-vendor signaling congestion	Simulate congestion	Traffic rerouted
42	Inter-vendor roaming authentication	Authenticate roamer on foreign MSC	Auth successful
43	Inter-vendor SMSC routing	Route SMS via different vendor SMSC	SMS delivered
44	Inter-vendor call forwarding	Forward call across networks	Call forwarded
45	Inter-vendor call barring	Apply call barring	Barring enforced
46	Inter-vendor supplementary services	Use call hold, transfer, etc.	Services functional
47	Inter-vendor emergency call	Make emergency call	Call routed correctly
48	Inter-vendor service denial	Deny service due to policy	Access blocked
49	Inter-vendor protocol upgrade	Upgrade protocol version	Upgrade successful
50	Inter-vendor protocol downgrade	Downgrade protocol version	Downgrade handled

SS7 Feature : Security (Basic)

Security (Basic) - Testcases

#	Test Case	Description	Expected Result
1	Valid Signaling Message	Send valid SS7 message	Message accepted
2	Tampered Message	Modify message in transit	Message rejected
3	Spoofed Origin Address	Use fake sender address	Message blocked
4	Replay Attack	Resend captured message	Message rejected
5	Invalid Message Format	Send malformed message	Message dropped
6	Unauthorized Node Access	Send from unauthorized node	Access denied
7	Message Integrity Check	Enable integrity check	Tampering detected
8	Message Without Integrity	Disable integrity check	Message accepted with warning
9	Message with Invalid Checksum	Corrupt checksum	Message rejected
10	Message with Valid Checksum	Send correct checksum	Message accepted
11	SCCP Spoofing Attempt	Spoof SCCP address	Message blocked
12	MAP Spoofing Attempt	Spoof MAP message	Message rejected
13	TCAP Spoofing Attempt	Spoof TCAP dialog	Dialog rejected
14	ISUP Spoofing Attempt	Spoof ISUP message	Call setup blocked
15	Unauthorized MAP Operation	Use restricted MAP op	Operation denied
16	Unauthorized TCAP Operation	Use restricted TCAP op	Operation denied
17	Message Flooding	Send excessive messages	Rate limited
18	Message Rate Limiting	Enable rate control	Excess messages dropped
19	Message Authentication Failure	Fail auth check	Message rejected
20	Message Authentication Success	Pass auth check	Message accepted
21	Message from Unknown Node	Send from unknown point code	Message dropped
22	Message from Trusted Node	Send from known point code	Message accepted
23	Message with Invalid Point Code	Use invalid code	Message rejected
24	Message with Valid Point Code	Use valid code	Message accepted
25	Message with Invalid Subsystem	Use unknown subsystem	Message dropped
26	Message with Valid Subsystem	Use known subsystem	Message accepted
27	Message with Expired Timestamp	Use old timestamp	Message rejected
28	Message with Valid Timestamp	Use current timestamp	Message accepted
29	Message with Invalid Sequence	Break sequence order	Message rejected
30	Message with Valid Sequence	Maintain sequence	Message accepted
31	Message with Invalid Routing Label	Corrupt routing label	Message dropped
32	Message with Valid Routing Label	Use correct label	Message routed
33	Message with Invalid GT	Use fake Global Title	Message rejected
34	Message with Valid GT	Use correct GT	Message routed
35	Message with Invalid IMSI	Use fake IMSI	Message rejected
36	Message with Valid IMSI	Use real IMSI	Message accepted
37	Message with Invalid MSISDN	Use fake MSISDN	Message rejected
38	Message with Valid MSISDN	Use real MSISDN	Message accepted
39	Message with Invalid MAP Version	Use unsupported version	Message rejected
40	Message with Valid MAP Version	Use supported version	Message accepted
41	Message with Invalid Protocol ID	Use wrong protocol ID	Message dropped
42	Message with Valid Protocol ID	Use correct protocol ID	Message accepted
43	Message with Invalid Dialog ID	Use reused dialog ID	Dialog rejected
44	Message with Valid Dialog ID	Use unique dialog ID	Dialog accepted
45	Message with Invalid Transaction ID	Use fake transaction ID	Transaction rejected
46	Message with Valid Transaction ID	Use correct ID	Transaction accepted
47	Message with Invalid Address Indicator	Use wrong indicator	Message dropped
48	Message with Valid Address Indicator	Use correct indicator	Message routed
49	Message with Invalid Nature of Address	Use wrong nature	Message rejected
50	Message with Valid Nature of Address	Use correct nature	Message accepted

SS7 Feature : Service Flexibility

Service Flexibility - Testcases

#	Test Case	Description	Expected Result
1	Toll-Free Call Setup	Dial toll-free number	Call routed to correct destination
2	Invalid Toll-Free Number	Dial malformed toll-free number	Call rejected
3	Prepaid Call Authorization	Initiate prepaid call	Balance checked and call allowed
4	Prepaid Call with Insufficient Balance	Call with low balance	Call blocked
5	Prepaid Balance Deduction	Call in progress	Balance deducted in real time
6	Prepaid Balance Top-Up	Recharge account	Balance updated
7	Number Portability Lookup	Dial ported number	Correct routing via NPDB
8	Number Portability Failure	NPDB unavailable	Call rerouted or failed
9	Intelligent Network Trigger	Trigger IN service	SCP invoked
10	IN Service Timeout	SCP does not respond	Default action taken
11	Call Forwarding Activation	Enable call forwarding	Forwarding confirmed
12	Call Forwarding Execution	Call to forwarded number	Call redirected
13	Call Barring Activation	Enable call barring	Barring confirmed
14	Call Barring Execution	Attempt barred call	Call blocked
15	Call Waiting Activation	Enable call waiting	Feature activated
16	Call Waiting Notification	Receive second call	Notification received
17	Call Hold and Resume	Hold and resume call	Call continues
18	Call Transfer	Transfer active call	Call transferred
19	CAMEL Prepaid Call	Use CAMEL for prepaid	Call controlled by SCP
20	CAMEL Roaming Call	Roaming call with CAMEL	SCP invoked successfully
21	CAMEL Service Failure	SCP unavailable	Default call handling
22	SMS Charging	Send SMS from prepaid	Balance deducted
23	SMS to Toll-Free Number	Send SMS to toll-free	Message delivered or rejected
24	Location-Based Routing	Route based on location	Correct destination
25	Time-Based Routing	Route based on time	Correct destination
26	VPN Call Setup	Call within VPN group	Call connected
27	VPN Call Restriction	Call outside VPN group	Call blocked
28	Short Code Dialing	Dial short code	Service triggered
29	Short Code with Invalid Format	Dial invalid short code	Call rejected
30	Service Trigger on Busy	Call busy number	Alternate service triggered
31	Service Trigger on No Answer	No answer from callee	Alternate service triggered
32	Service Trigger on Unreachable	Callee unreachable	Alternate service triggered
33	USSD Session Start	Initiate USSD	Session started
34	USSD Session Timeout	No response in session	Session terminated
35	USSD with Prepaid Balance	Check balance via USSD	Balance displayed
36	USSD with Invalid Code	Dial invalid USSD	Error message shown
37	Service Profile Download	Download from HLR	Profile received
38	Service Profile Update	Update subscriber profile	Changes applied
39	Service Profile Corruption	Corrupt profile data	Error detected
40	Service Profile Recovery	Restore profile	Profile restored
41	Multi-SIM Service Support	Use dual SIM device	Both SIMs functional
42	Multi-IMSI Service Support	Use multiple IMSIs	All IMSIs supported
43	Multi-Operator Service Access	Access services across operators	Services available
44	Multi-Technology Service Access	Use 2G/3G/4G/5G	Services consistent
45	Service Access via Roaming	Use services while roaming	Services available
46	Service Access Denial	Blocked service	Access denied
47	Service Access Logging	Log service usage	Logs complete
48	Service Access Monitoring	Monitor service usage	Anomalies flagged
49	Service Access Alerting	Alert on misuse	Alert triggered
50	Service Access Policy Enforcement	Enforce service rules	Policy applied

Reference links

• Reference links