448

Port 448/tcp carries ddm-ssl, the SSL/TLS-encrypted variant of IBM's Distributed Data Management (DDM) remote-database access protocol; like its plaintext sibling on 446/tcp, it belongs on a trusted internal or VPN-protected network rather than being exposed directly to the public internet.

IANA's Service Names and Port Numbers registry dual-registers 448 as ddm-ssl on both TCP and UDP, description "DDM-Remote DB Access Using Secure Sockets," assignee and contact Steven Ritland. The Reference column is blank — no RFC documents this assignment — and no registration or modification date is recorded for the entry.

DDM is IBM's architecture for remote access to host data resources; DRDA (Distributed Relational Database Architecture) is the relational-database application built on it. IANA registers two companion ports: 446 (ddm-rdb, the base plaintext DRDA channel) and 447 (ddm-dfm, distributed file management) — 448 adds SSL/TLS to the same DRDA traffic. Generic port-reference sources tie the service to IBM i (AS/400/iSeries) database connectivity, consistent with the IANA description, but this is not independently corroborated by primary IBM documentation.

As of an August 2026 check, SANS Internet Storm Center's port-448 tracker recorded only routine background scanning — daily top-source hit counts in the single digits to low 30s — with no CVE entries or abuse reports tied to the port. No malware or trojan association is documented for port 448 as of that check.

IANA assignment

ddm-ssl — "DDM-Remote DB Access Using Secure Sockets"; Reference column blank; assignee and contact Steven Ritland; dual-registered 448/tcp + 448/udp [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry ddm-ssl 448/tcp, ddm-ssl 448/udp

Range class

well-known (0–1023); source artifact labels this the "system" range [Confirmed] — this site's own tooling (port 448 entry)

Registration/modification dates

both blank in the IANA registry for this entry — left null, not fabricated [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry ddm-ssl 448/tcp

Prevalence

nmap-services open-frequency 448/tcp = 0.00005 (~0.005%); 448/udp = 0.000511 (~0.0511%) [Confirmed] — this site's own tooling (port 448 entry)

Related ports

446/tcp ddm-rdb (unencrypted DDM remote relational database access — the base protocol this port secures); 447/tcp ddm-dfm (DDM distributed file management) [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry ddm-rdb 446/tcp, ddm-dfm 447/tcp

Primary use

SSL/TLS-encrypted IBM DDM/DRDA remote database access — the secure counterpart to the plaintext ddm-rdb service on 446/tcp [Confirmed/Likely] — the IANA Service Name and Transport Protocol Port Number Registry ddm-ssl 448/tcp, https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=448

Other/unofficial uses

none corroborated as of an August 2026 search; a single uncorroborated SEO-style port-list mention of a Windows "DDEKit"/Dynamic Data Exchange association was found but excluded for lack of independent sourcing [Unknown]

Security implications

SANS ISC shows only routine background scanning as of an August 2026 check, no CVE or abuse-report entries; no malware/trojan association documented

Typically seen on

IBM i (AS/400/iSeries) hosts using DDM/DRDA database connectivity over SSL/TLS, per generic secondary port-reference sources — not independently corroborated by primary IBM vendor documentation in this search

Analyst note

treat an open 448/tcp as a probable TLS-secured DDM/DRDA database channel best confined to a trusted or VPN-connected network; investigate any listener not tied to a known IBM i or DB2 deployment.

Port 448/udp carries ddm-ssl, IBM's TLS-secured member of the DDM database-access port family; it should stay restricted to authenticated, trusted-network or VPN-connected clients rather than sit exposed to the open internet.

IANA's Service Name and Transport Protocol Port Number Registry lists ddm-ssl as "DDM-Remote DB Access Using Secure Sockets," dual-registered on both 448/tcp and 448/udp under the same name, assignee Steven Ritland, with a blank Reference column — no RFC defines the protocol, and no registration or modification date is recorded for either row.

The ddm-ssl name mirrors 446/ddm-rdb ("DDM-Remote Relational Database Access," plaintext) as its SSL/TLS-secured counterpart; the adjacent port 447/ddm-dfm ("DDM-Distributed File Management") is a related but distinct plaintext DDM-family service, not itself database access.

IBM's own support and documentation pages describe enabling SSL/TLS for DDM on IBM i (AS/400/iSeries/System i) systems to secure remote DB2 for i database connections, though direct retrieval of those pages returned HTTP 403 in this search, so the identification is tagged Likely rather than Confirmed.

No non-IBM software was found using port 448 in an August 2026 search; the IBM i DDM/DRDA server and its DB2 for i database engine are the only applications documented against this port, consistent with an IBM-associated registry assignee rather than a broadly adopted general-purpose protocol.

Measured prevalence is low: the nmap-services open-frequency data bundled with this site records 448/udp at approximately 0.000511 (about 0.05% of scanned hosts) and 448/tcp at approximately 0.00005 (about 0.005%). Third-party lookup sites rate the SSL-secured variant as lower risk than its plaintext siblings, and no CVE or malware association was found for this port as of an August 2026 search.

IANA assignment

ddm-ssl — "DDM-Remote DB Access Using Secure Sockets"; reference (blank — no RFC cited in IANA registry); assignee Steven Ritland; dual-registered 448/tcp + 448/udp [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry ddm-ssl 448/udp

Range class

well-known (System Ports, 0–1023) [Confirmed] — IANA Service Name and Transport Protocol Port Number Registry

Prevalence

nmap-services open-frequency 448/udp ≈ 0.000511 (~0.051%); 448/tcp ≈ 0.00005 (~0.005%) [Confirmed] — this site's own tooling

Related ports

448/tcp (same ddm-ssl service name, dual-registered); 446/tcp+udp (ddm-rdb, plaintext DB access); 447/tcp+udp (ddm-dfm, plaintext file management) [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry ddm-rdb 446/tcp, the IANA Service Name and Transport Protocol Port Number Registry ddm-dfm 447/tcp

Primary use

SSL/TLS-secured DDM (Distributed Data Management) remote database access — the encrypted counterpart to 446/ddm-rdb — used by IBM i (AS/400/iSeries/System i) systems to reach DB2 for i databases [Likely] — https://www.ibm.com/support/pages/ssltls-enablement-ddm-ibm-i-ibm-i, https://www.ibm.com/docs/en/i/7.2.0?topic=network-ports-port-restrictions

Other/unofficial uses

none found beyond the IBM i DDM/DRDA server as of an August 2026 search

Security implications

third-party lookup sites rate DDM-SSL low-risk due to TLS encryption; no CVE or malware association found as of an August 2026 search; DShield/SpeedGuide scan-activity data could not be retrieved (HTTP 403)

Typically seen on

IBM i (AS/400, iSeries, System i) database servers using SSL-secured DDM for remote DB2 for i access

Analyst note

Treat 448/udp as IBM i/DB2-for-i remote database traffic and restrict it to trusted networks or VPN — encryption reduces eavesdropping risk relative to plaintext DDM/DRDA but does not make broad internet exposure of a database-access port appropriate.