PrettyDiameter

PrettyDiameter is a production-oriented fork of freeDiameter focused on Diameter Routing Agent (DRA) deployments: fixed SCTP source binding per peer, safer relay behavior, HTTP route statistics, and operator-ready configuration samples.

License

This project retains the freeDiameter BSD license (see LICENSE). PrettyDiameter changes are offered under the same terms. Copyright for upstream code remains with WIDE Project and NICT; PrettyDiameter additions are documented in commit history.

Features

Feature	Branch	What it does
Per-peer SCTP source bind	feature/per-peer-sctp-src-bind	SrcIP, SrcPort, LocalHost, LocalRealm on ConnectPeer for stable outbound four-tuples and per-link Origin-Host
DRA relay routing fixes	feature/per-peer-sctp-src-bind	LocalHost no longer treated as global Identity for local delivery / loop detection; answers return to correct peer
dra_rtstats	feature/dra-rtstats	HTTP UI: per-peer message counters, optional route_match reporting, optional dh_replace
Routing config samples	feature/dra-routing-samples	Commented rt_default snippets: realm routing, DH→MME, IMSI prefix steering
PCAP analysis helpers	feature/pcap-analysis-tools	Optional Python tools for IMSI / GTP / PFCP correlation in lab troubleshooting

Architecture (where this fits)

  [MME]──S6a──┐                    ┌──S6a──[HSS]
              │    PrettyDiameter  │
  [DRA peer]──┼──── (relay) ──────┼──[HSS]
              │    • rt_default    │
              │    • dra_rtstats   │
              └────────┬───────────┘
                       │ N4 (PFCP) / GTP — outside Diameter; use PCAP tools
                 [SGW-C / UPF]

Per-peer SCTP bind (SrcIP / SrcPort / LocalHost)

Used on outbound ConnectPeer links when the operator requires:

• A fixed local IP and port on the wire (firewall / whitelist / no SNAT)
• A different Origin-Host per link (presentation) while keeping one global DRA Identity

Does not add client/server modes: freeDiameter still listens globally and connects via ConnectTo (see doc/freediameter.conf.sample).

Relay routing

• Destination-Host matching uses ConnectPeer Diameter-Id (+100 FINALDEST).
• Destination-Realm rules in rt_default can still outscore MME if HSS has DR=… += 100 and MME only has +100 — use DH= rules in doc/dra_rt-dh-mme-routing.snippet.
• LocalHost affects CER/CEA and outbound Origin-Host on that link only; it is not a separate routing target.

dra_rtstats

Load as extension; serves HTML on configured Port (default 8088). Use for:

• Link up/down and message mix (AIR, ULR, CLR, …)
• Verifying route_match rules vs actual next-hop peer
• Optional dh_replace before routing-out (rewrite presented DH to real MME peer)

Build

mkdir build && cd build
cmake -DCMAKE_BUILD_TYPE=MaxPerformance ..
cmake --build . -j$(nproc)
cmake --install .

Enable extensions in CMakeLists.txt / build options as per upstream freeDiameter, including dra_rtstats.

Configuration

File	Purpose
doc/sctp-per-peer-src-bind.patch-notes.md	Per-peer SCTP / LocalHost reference
doc/dra_rtstats.conf.sample	HTTP stats and optional route_match / dh_replace
doc/dra_rt-realm-routing.snippet	Example DR= rules for rt_default
doc/dra_rt-dh-mme-routing.snippet	Example DH= rules when HSS wins on realm
doc/deploy-dra-server.sh	Generic build/install example

PCAP tools (optional)

pip install scapy
python tools/analyze_imsi_pcap.py capture.pcap 999011234567890
python tools/analyze_imsi_gtp_pfcp_teid.py capture.pcap 999011234567890

Requires explicit PCAP path and IMSI; no operator data is stored in the repository.

Upstream

Based on freeDiameter master. PrettyDiameter is maintained as a separate GitHub project for DRA-focused improvements without replacing the upstream project.